Robin Williams reportedly fell off the wagon while making 'The Crazy Ones'.
The late 63-year-old actor - who got sober in 1983 before relapsing briefly in 2003 - stunned cast and crew members on the CBS show when he insisted on drinking real alcohol when filming a scene at Beverly Hills restaurant Spago last May.
A source told the New York Post newspaper's Page Six column: "Robin insisted on a real drink. No one had seen him drinking before this. One drink led to another, but it seemed to calm him down."
According to the insider, Robin - who checked into rehab in June to "maintain his sobriety" - was said to frequently infuriate his co-stars on the show because he often went off script, forcing the likes of Sarah Michelle Gellar to have to improvise their responses.
He also complained he "had a bad feeling" about the lack of chemistry on the set of the show, which was cancelled after just one season, and spent most of his downtime with his beloved Pug Leonard.
The source said: "He brought it everywhere with him. When he wasn't filming a scene, he was holding and petting and fawning over the dog."
It was recently revealed that Robin - who was found hanged at his California home on Monday (11.08.14) - had attended an Alcoholics Anonymous (AA) meeting shortly before he died.
Comedian and fellow AA member Argus Hamilton said: "He was at a meeting on Saturday. He had got out of rehab and was sober at the meeting."

Chris Brown has been praised by a judge for his good behaviour.
The 'Yeah 3x' hitmaker appeared in a Los Angeles court yesterday (13.08.14) for a progress report on his probation and the hearing was told all his random drug tests were negative and he had been attending bi-weekly therapy sessions.
As a result of his positive report, the judge agreed to a request from the 25-year-old singer's lawyer to have his drug testing reduced from three times a week to June.
While Chris - who was placed on probation for five years and sentenced to six months community service for assaulting then-girlfriend Rihanna in 2009 - hasn't spoken directly about his good report, he made fans aware of the situation.
He retweeted a post from CNN reporter Alan Duke which read: "Judge just praised @chrisbrown for a good probation report, noting he's tested negative on all drug tests since release from jail."
The 'Run It' star will next appear in court for a probation hearing on October 23 and his probation comes to an end in January 2015.
Chris - who was released from jail on June 2 after spending two months behind bars for allegedly making threats about using guns while seeking anger-management treatment in rehab - recently vowed to be a "real man" and learn from his past behaviour.
Posting a picture of himself in court wearing an orange jumpsuit, he wrote: "I been through a lot in my life. Made a lot of mistakes along the way. But through it all I've always been true to myself and through God I've been able to take care of my family! I should regret some things but I think the lessons learned will shape me into a real man. I'm grateful and appreciative! Thank you for life!"

'Guardians of the Galaxy' director James Gunn is already working on a sequel to the sci-fi film.
The first movie - starring Zoe Saldana, Bradley Cooper, Vin Diesel and Chris Pratt - opened in cinemas over the last couple of weeks, but Gunn is refusing to let the dust settle, revealing he has already developed a "basic story" for the sequel.
He told Empire: "I've thought a lot about where these characters are going and where they came from, things we've gotta find out. There has been a lot of world building we've done that we get to play with in the second movie.
"There have been a lot of documents passed around about who Peter Quill's father is, and things like that, between a select two or three of us. That's been part of the plan since the beginning, that's something I had to work out and I worked it out before we shot the screenplay."
Although Gunn, 44, admits the sequel is still in its infant stages, the director is excited by the creative process.
He added: "Sometimes you have ideas and you write them down and they're too convoluted on paper and it's too many ideas for one thing or it's not enough ideas or whatever and so that could easily change, but I know a lot about who these characters are and where they came from and where they're going."

Tara Reid won't rule out having more cosmetic surgery.
The 'Sharknado 2: The Second One' star previously underwent liposculpting to remove fat from her stomach but the procedure went wrong and she was left with scarring following corrective surgery.
Despite her bad experience, Tara - who also had a breast enlargement operation - would consider going under the knife again.
The 38-year-old actress said: "I can't say I'm never going to have more surgery as I don't know how I'll feel in a few years. Right now, I'm happy with my body, though.
"But the mental and physical pain I went through after I had the surgery was horrific. I went through two years of living in denial and everyone saying how bad my body was."
After shooting to fame in 1999 comedy film 'American Pie', Tara has attracted attention for her alleged party girl lifestyle, but is adamant she has a sensible attitude towards alcohol now.
She told Closer magazine: "I've had my fun but I still like to go out with my friends and have a drink. I don't need to be sober. I can have a glass of wine if I want one."

Neil Patrick Harris fell in love with David Burtka all over again after they had children.
The 'How I Met Your Mother' star, who welcomed twins, Gideon and Harper, into the world in 2010 via a surrogate mother, says watching his fiancé, 39, interact with their son and daughter has made him appreciate David more.
Speaking about the secret to their long-lasting relationship, the 41-year-old star told the September issue of Glamour magazine: "I think you have to find new elements that turn you on, and not only sexually. Having kids was one of those great moments for me.
"Watching David become another level of person, mastering this other domain, made me look at him with a whole other set of appreciative eyes. That sort of made me re-fall in love with him."
Neil, who confirmed he is gay in 2006, also admits he felt "unsettled" during sexual encounters with women when he was younger.
He said: "In high school all my friends were sleeping with girls, and it just seemed like that's what one did. So therefore that's what I did, but it left me feeling unsettled, as if I had somehow done it wrong. That's not a good feeling."
He added: "But now I think it's easier to avoid that fate. Today, it's cool to see a happy lesbian couple who are high school juniors. Better that than have those two girls marry people they're not attracted to, have three kids, and then come out when they're 50."

Ciara says she feels "a whole new spiritual energy" after splitting from fiancé Future.
The 28-year-old singer, who dumped the rapper after she reportedly found out he was cheating on her, plans to express all of her feelings through her new music and insists she is "very, very happy."
The 'Goodies' hitmaker, who has three-month-old son Future Jr., told UsMagazine.com on Tuesday (12.08.14), one day before news of their breakup hit the headlines: "I'm in a much more clairvoyant place in my life. So, I want to express that through my music."
She added: "I think that when you become a mom... you don't really worry about the small stuff. I'm just way more centred. It makes you focus even more on what your goals are in life. And I just feel a whole new spiritual energy that's happening."
Ciara plans to "stay focused" on her career and insists she "can't waste time" on things that don't matter to her.
She said: "My son has been the best thing that has happened in my life. He has been amazing and he is truly heaven-sent. And so, I just feel all that love.
"I want to be one of those moms and women that when I look back, I know that I always stayed focused. It's about keeping your eyes on the prize. Before I had a child, I had goals. And I still have to accomplish those goals, but now that I have a child, I have more goals to accomplish. So I can't waste time. I have to go for it. It's actually pushing me harder, and forward."
Speaking about motherhood, she added: "It's a great thing. I wouldn't trade it for the world, and I'm very, very happy."

Carrie Underwood is in talks to perform at the half time show of the 2015 Super Bowl.
The 31-year-old former 'American Idol' winner is tipped to be the musical act at the NFL Super Bowl XLIX, held at the University of Phoenix Stadium in Glendale, Arizona, on February 1 next year.
Sources told sports gossip blog www.TerezOwens.com that the 'Blown Away' hitmaker will most likely headline the event, which is one of the biggest in America, watched by an estimated 114 million every year, as football fans already know her from 'Sunday Night Football,' and organisers are confident that country music is now mainstream.
An official announcement isn't expected to be made until early next month.
Super Bowl performances usually feature a number of special guests and Miranda Lambert could join Carrie onstage, as they recently released their duet, 'Something Bad.'
Bruno Mars performed at last year's event alongside the Red Hot Chili Peppers, while Beyoncé Knowles was joined on stage by her former Destiny's Child band members, Kelly Rowland and Michelle Williams, during her performance in 2012.
Other past performers include Madonna, whose show proved to be controversial when special guest star M.I.A. stuck her middle finger up to a live TV camera.

Christina Aguilera wants to unveil her post-baby body in Playboy.
The 'Your Body' hitmaker, who recently posed nude to show off her growing baby bump on the cover of the latest issue of V magazine, is reportedly eager to strip down again after she gives birth to her second child and gets back in shape.
A source close to the 33-year-old star, who already has a six-year-old son, Max, told In Touch Weekly magazine: "She wants to do Playboy. This is something she wanted to do even before she got pregnant. Christina's always loved her body."
The 'Voice' USA mentor, who lost 20 pounds last year after embarking on a strict diet and fitness regime, is said to have hired a nutritionist to help her maintain a healthy weight throughout her pregnancy and plans to get back to her pre-baby weight before agreeing to bare all in the magazine.
The insider said: "It won't be too hard. She even hired a nutritionist.
"She's determined to do this. Christina is planning to show off her assets."
The blonde beauty, who is engaged to Matthew Rutler and is expecting a baby girl, recently said she is "proud" of her figure.
She said: As a woman, I'm proud to embrace my body through all stages of life, staying fearless and confident in surrendering to the unknowns the future has in store."

Kris Jenner is happy that Kim Kardashian West is moving "right around the corner" from her.
The 'Keeping Up with the Kardashians' star is thrilled her daughter, who moved into her home in Calabasas, California last year, recently bought a new $20 million mansion in nearby Hidden Hills with husband Kanye West, as she was upset about their original plans to live in Bel Air with their 13-month-old daughter, North.
Asked when the couple is moving out, the 58-year-old family matriarch told E! News: "Oh god somebody tell me, just kidding Kim. I thought when she got this new house that she would be moving right out and I was getting a little sad about it, but then realised that North, her and Kanye have lived with me for almost a year and a half now, so it's been a really wonderful time, but they're going to be right around the corner so I feel better about that."
The couple moved in with Kris before North's birth in June 2013 in order to renovate an $11 million home in Bel Air.
They recently decided to put that property on the market and bought their lavish new home, as they got fed up of waiting for the extensive work to be completed.
Kris is very happy they are no longer moving almost an hour away.
She said: "Well that's why I'm happy now. [It's] right down the street. I can walk there."

Robin Williams will be honoured during a special segment at the upcoming Emmy Awards.
Organisers of the 66th annual event, set to take place in Los Angeles on August 25, plan to include plenty of tributes to the 63-year-old actor, whose body was discovered by his personal assistant at his home in Tiburon, California on Monday (11.08.14) after he committed suicide.
Executive producer of the star-studded ceremony Don Mischer told PEOPLE.com: "Plans for the In Memoriam segment are in discussion. While we are all still coming to terms with this week's tragic news, we are working to give Robin Williams the proper and meaningful remembrance he so well deserves."
The In Memoriam section of the ceremony usually pays tribute to Hollywood stars and respected members of the film industry who died over the previous year.
The 'Mrs. Doubtfire' star's family members and close friends have started planning the Oscar-winning actor's private funeral and a public memorial is also in the works.
A source recently said: "Everyone is obviously just stunned that Robin committed suicide . . . his family is holed up together and beginning to make plans for a very private funeral.
"There will most likely be a public memorial to celebrate his life that his fans can be a part of."

Kim Kardashian West says Kanye West has inspired her to be more outspoken and real.
The 33-year-old reality TV star, who married the rapper, with whom she has 13-month-old daughter, North, in Italy in May, claims she has zero time "for anything else but the truth" these days.
Asked if she has become bolder since becoming a mother, the 'Keeping Up with the Kardashians' star said: "Yeah, I think so. I think when you have a baby there's like no time for any like s**t. Excuse my language. You don't have time for it and sometimes I see things and I'm like, 'I'm not gonna let that slide. This person was wrong.' Or whatever I'm feeling I speak my mind a little bit more after I've had our daughter."
She added: "I don't know if it's a combination of being married to someone that's super honest and open and says whatever he wants whenever he wants to or just not having time really for anything else but the truth and just being real."
Despite admiring Kanye's honesty, Kim, who says North first started calling the 'New Slaves' hitmaker "daddy and dad" at seven months old, doesn't always understand what her husband is saying during some of his infamous on-stage rants.
She told 'Watch What Happens Live': "Nothing that he says would embarrass me. There is some times where he would talk about something that I might not understand the point that he's really trying to get across and then I really understand it after the fact, and I totally believe in him and what he's saying. It's really cool to see that he just speaks the truth so I respect his rants and I like what he says."

Robin Williams was reportedly sleeping up to 18 hours a day before his death.
The 63-year-old actor, whose body was found by his personal assistant after he hanged himself at his home in Tiburon, California on Monday (11.08.14), also "wasn't eating" in the weeks before taking his own life due to his severe depression.
A source told gossip website RadarOnline.com: "Robin had been suffering from depression and would often sleep a majority of the day and night. His bedroom had black out curtains, because Robin didn't want light in his bedroom.
"He wasn't eating and was just having problems getting out of bed. He would often complain that he was just so tired, even after sleeping 20 hours."
The 'Mrs. Doubtfire' actor sought relief from his personal struggles in his work for much of his life.
The insider said: "Robin's comedic talent came from the sadness he had in his personal life . . . the laughter was his coping mechanism.
"He had been battling depression for most of his adult life . . . it was always there."
Family members and friends have started planning the Oscar-winning star's private funeral.
The source said: "Everyone is obviously just stunned that Robin committed suicide . . . his family is holed up together and beginning to make plans for a very private funeral.
"There will most likely be a public memorial to celebrate his life that his fans can be a part of."