Heartfelt tributes continue to pour in from across the world as relatives, friends, fans, directors and Hollywood stars mourn the loss of actor and comic Robin Williams, who has been found dead at his home in Northern California from an apparent suicide. He was 63.

Williams's third wife Susan Schneider released a statement on Monday night in which she said: "This morning, I lost my husband and my best friend, while the world lost one of its most beloved artists and beautiful human beings. I am utterly heartbroken."

In his final posting on Instagram on 1 August, Williams had wished his daughter Zelda a happy 25th birthday with a photo of the pair, saying: "Quarter of a century old today but always my baby girl. Happy Birthday @zeldawilliams Love you!".

This is the last picture Robin Williams posted on Instagram on his daughter Zelda's 25th birthday

Fellow comedy star Steve Martin led tributes to his friend in a tweet: "I could not be more stunned by the loss of Robin Williams, mensch, great talent, acting partner, genuine soul."

Actress Sarah Michelle Gellar said her life “is a better place because I knew Robin Williams”. Gellar, who worked with Williams on what would be his final TV appearance for The Crazy Ones, explained to People magazine how Williams had become a paternal figure to her.

“To my children he was Uncle Robin, to everyone he worked with, he was the best boss anyone had ever known, and to me he was not just an inspiration but he was the father I had always dreamed of having.”

Robin Williams: A career in pictures Show all 30 1 /30 Robin Williams: A career in pictures Robin Williams: A career in pictures Robin Williams 1980: Robin Williams in the world-famous Mork and Mindy series that launched his career. Rex Robin Williams: A career in pictures Robin Williams 1984: Williams in 'Moscow On The Hudson'. The actor earned his first Golden Globe nomination for his turn as a Russian circus performer in this 1984 hit. Robin Williams: A career in pictures Robin Williams 1987: Williams in the critically acclaimed 'Good Morning, Vietnam'. Williams ad-libbed all the radio broadcast scenes from this 1987 film about a radio DJ sent to Vietnam to entertain the US troops serving out there. Rex Features Robin Williams: A career in pictures Robin Williams 1989: Robin Williams appeared with Robert Sean Leonard and Josh Charles in 'Dead Poets Society' as English teacher John Keating - or the “slightly more daring O Captain, My Captain”. Touchstone Pictures Robin Williams: A career in pictures Robin Williams 1990: Williams and Robert De Niro in Awakenings, an emotional film that saw Williams portray a British neurologist who administered a drug to catatonic patients that briefly awoke them from decades of catatonia. Robin Williams: A career in pictures Robin Williams 1991: Williams appeared as an adult Peter Pan forced to return to Neverland to rescue his children in 'Hook'. The film received mixed reviews but proved popular at the box office. Robin Williams: A career in pictures Robin Williams 1992: Williams in 'Toys'. The film followed a military general after he inherits a toy factory and decides to produce war toys. Robin Williams: A career in pictures Robin Williams 1993: Williams appeared in one of his best-loved roles in Mrs Doubtfire, where he played an actor disguising himself as a female housekeeper in order to spend more time with his children. Robin Williams: A career in pictures Robin Williams 1995: Williams appeared as man released from a board game after being trapped for decades inside it in the blockbuster 'Jumanji'. Robin Williams: A career in pictures Robin Williams 1996: Williams starred opposite Jennifer Lopez in 'Jack', a film about a young boy who ages four times faster than other children. Robin Williams: A career in pictures Robin Williams 1997: Williams appeared alongside Matt Damon in 'Good Will Hunting', a film that won him an Oscar for his portrayal of psychologist Sean Maguire. As he accepted his award, a touched Williams warned the audience: "Oh man, this might be the one time I’m speechless". Miramax Pictures Robin Williams: A career in pictures Robin Williams 1997: The box-office hit Flubber saw Williams take the role of Professor Philip Brainard, who creates the unstoppable green goo Flubber in his bid to produce a new energy source. Robin Williams: A career in pictures Robin Williams 1998: Williams gave a poignant turn as Dr Hunter 'Patch' Adams, an unqualified doctor who treats patients with laughter in 'Patch Adams' . Robin Williams: A career in pictures Robin Williams 1998: Williams stars alongside Cuba Gooding, Jr in 'What Dreams May Come', a film that follows American physician Chris Nielsen's journey through the afterlife after he is killed in a car crash. Robin Williams: A career in pictures Robin Williams 1999: Robin Williams, Bob Balaban (left), and Armin Mueller-Stahl star in the movie 'Jakob the Liar' about a Jewish shopkeeper who uses his imagination to engender hope throughout a Jewish ghetto in Nazi-occupied Poland in 1944. Rex Robin Williams: A career in pictures Robin Williams 1999: American Science Fiction drama 'Bicentennial Man' followed an android (Williams) as he experiences emotions and becomes more human Robin Williams: A career in pictures Robin Williams 2002: Williams took a more sinister role as reclusive crime writer and murderer Walter Finch in 'Insomnia'. Warner Bros Pictures Robin Williams: A career in pictures Robin Williams 2002: Williams undertook an unsettling, psychopathic role in One Hour Photo, where he played a photo lab technician obsessed with a family who frequented the store. Robin Williams: A career in pictures Robin Williams 2002: Williams starred alongside Danny DeVito in 'Death to Smoochy', a film about a corrupt children's television host disgraced by an FBI sting. Robin Williams: A career in pictures Robin Williams 2005: Robin Williams stars in 'The Big White', a film about a financially struggling travel agent trying to make a bogus life insurance claim in order to pay for his wife's Tourette treatment. Robin Williams: A career in pictures Robin Williams 2006: Williams and Ben Stiller star in 'Night at the Museum'. Williams will appear in upcoming film "Night at the Museum: Secret of the Tomb," playing the statue of Teddy Roosevelt who comes to life at night. Robin Williams: A career in pictures Robin Williams 2006: Robin Williams, Jeff Daniels and Cheryl Hines star in roadtrip comedy 'R.V.', which followed the tribulations of a dysfunctional family. Robin Williams: A career in pictures Robin Williams 2006: Williams took the leading role in the political comedy drama 'Man of the Year' about a comedian who decides to run for President and finds himself mistakenly elected. Robin Williams: A career in pictures Robin Williams 2007: Robin Williams and Freddie Highmore in 'August Rush', where Williams played a homeless musician who teaches children living on the streets music and employs them as performers. Robin Williams: A career in pictures Robin Williams 2007: Robin Williams, Mandy Moore and John Krasinski starred in 'License to Wed'. Williams played a reverend who places a couple through a series of tests to see if they should marry in his church. The rom-com was poorly received by critics. Robin Williams: A career in pictures Robin Williams 2010: Robin Williams and John Travolta star in 'Old Dogs', a comedy that sees two friends and owners of a sports marketing firm struggle to deal with seven-year-old twins placed in their care. The film was nominated for four Golden Raspberry Awards. Robin Williams: A career in pictures Robin Williams 2013: Susan Sarandon, Robert De Niro and Robin Williams star in The Big Wedding Robin Williams: A career in pictures Robin Williams 2013: Williams starred as President Eisenhower in Lee Daniels' 'The Butler'. Robin Williams: A career in pictures Robin Williams 2014: Robin Williams with his Mork and Mindy co-star Pam Dawber in The Crazy Ones series. It was axed after one season. Robin Williams: A career in pictures Robin Williams 2014: Rob Williams stars in 'The Angriest Man in Brooklyn', the story of a bad-tempered man mistakenly told he has 90 minutes to live.

The tributes have also brought unique moments and acts of kindness to light, including from his Mrs Doubtfire co-star Lisa Jakub, who showed The Independent a letter Williams wrote to her school demanding she be allowed back after being expelled for taking time off to film.

In a Tweet today, comic Steve Carell said simply: "Robin Williams made the world a bit better", while director Steven Spielberg described his friend as "a lightning storm of comic genius, and our laughter was the thunder that sustained him".

The affection Williams was treated with by the wider world became evident in other efforts to remember the comic, with Hollywood’s Laugh Factory changing their sign to read: “Robin Williams Rest In Peace Make God Laugh.”

Meanwhile, fans in Boston headed to the bench where his character Dr Sean Maguire in Good Will Hunting conveyed the beauty and pain of worldly experience and the ‘true happiness’ experienced by being in love. "Your move, chief," one fan quoted on the paving in front of the bench, echoing the nickname Sean would sarcastically call his patient.

The bench shortly after the news of Williams' death broke (Nicholas Rabchenuk)

"Sorry guys, I went to see about a girl," another wrote, Damon's line at the film's denouement which proved that Sean's faith in love had rubbed off on him.

The star’s publicist Mara Buxbaum said Williams had recently been suffering from severe depression. Williams, who had struggled with addictions to drink and drugs in the past, had entered a Minnesota rehabilitation centre last month to help him maintain sobriety.

Video: Robin Williams - a life in films

His representatives at the time said Williams was not using drugs or alcohol but had gone to the centre to "fine-tune and focus" his sobriety after working a longer-than-usual schedule.

The Marin County Sheriff's office said it received an emergency call about midday on Monday, saying that Williams was unconscious and not breathing at his home near Tiburon, north of San Francisco. Local newspapers reported that he was pronounced dead shortly afterwards.

The thrice-married father-of-three was known to millions for his performances in films that ranged from the out and out manic comedy of Mrs Doubtfire, to more thought provoking fare likeDead Poets Society and The Fisher King. In many films, like Good Morning, Vietnam, Williams attracted widespread praise by successfully combining his gift for comedy with an exploration of more serious underlying themes.

Robin Williams in 1980 with Pam Dawber, his co-star in the Mork and Mindy TV series (Rex)

Nominated for the Best Actor Oscar three times, Williams won the Academy Award for Best Supporting Actor for the 1997 film Good Will Hunting.

As a stand-up, his explosive, improvisational talent was so hard to match that even the established star Billy Crystal once admitted that following Williams on stage was like trying to top the Civil War.

Such was his talent that he was allowed to ad-lib in many of his films – and his quick wit enlivened many a media appearance.

During a media tour for the 1990 film Awakenings, when director Penny Marshall mistakenly described the film as being set in a "menstrual hospital," instead of "mental hospital," Williams had the presence of mind to offer the explanation: "It's a period piece."

Robin Williams and Sally Field had great chemistry in Mrs Doubtfire

Williams once likened his act to the daily jogs he took across the Golden Gate Bridge. There were times he would look over the edge, one side of him pulling back in fear, the other insisting he could fly.

He also said: "Comedy can deal with the fear and still not paralyze you or tell you that it's going away. You say, OK, you got certain choices here, you can laugh at them and then once you've laughed at them and you have expunged the demon, now you can deal with them. That's what I do when I do my act."

Born in Chicago in 1951, Williams would remember himself as a shy kid who got some early laughs from his mother - by mimicking his grandmother. He opened up more in high school when he joined the drama club.

He began his career in stand-up comedy before first achieving widespread fame in the TV sitcom Mork and Mindy. The show ran from 1978 to 1982 and Williams was frequently allowed to indulge his talent for improvised comedy while playing Mork, an alien living on Earth.

During the late Seventies and early Eighties, however, Williams developed an addiction to cocaine.

All star cast: Susan Sarandon, Robert De Niro and Robin Williams star in The Big Wedding

Williams was a close friend of the comedian John Belushi who died of a cocaine and heroin overdose in 1982. Williams had enjoyed wild parties with Belushi and subsequently admitted that the death of his friend and the birth of his son prompted him to quit drugs: "Was it a wake-up call? Oh yeah, on a huge level.”

On August 9, 2006, Williams checked himself into a rehab centre, later admitting he was an alcoholic. His publicist announced: “After 20 years of sobriety, Robin Williams found himself drinking again and has decided to take proactive measures to deal with this for his own well-being and the well-being of his family.”

Williams, though, appeared to have recovered well enough to joke, on a recent tour: "I went to rehab in wine country. To keep my options open."

Robin Williams with his Mork and Mindy co-star Pam Dawber

In March 2009 Williams was also hospitalised by heart problems, and had to undergo surgery to surgery to replace his aortic valve.

A keen charity fundraiser Williams had, with his second wife, Marsha, founded the Windfall Foundation, to raise money for a wide variety of causes.

The US President Barack Obama joined the outpouring of tributes to Williams, calling the Hollywood star a "one of a kind" who "arrived in our lives as an alien - but ended up touching every element of the human spirit".

One of the final pictures Willams uploaded onto his Instagram account

Williams will appear in upcoming film "Night at the Museum: Secret of the Tomb," playing the statue of Teddy Roosevelt who comes to life at night, and holiday comedy "Merry Friggin' Christmas." He was also attached to a sequel to 1993 hit "Mrs. Doubtfire."

An autopsy is due to take place on Tuesday.