British actor Richard Griffiths, who millions of "Harry Potter" movie fans knew as the boorish and cruel Uncle Vernon Dursley, has died following complications after heart surgery. He was 65.

Tributes for the versatile, award-winning stage and screen actor poured in Friday shortly after his agent Simon Beresford announced the actor had died Thursday at the University Hospital in Conventry, central England.

Richard E. Grant, who starred with the distinctive looking actor in the 1987 cult classic "Withnail & I" tweeted on Friday: "My beloved 'Uncle Month' Richard Griffiths died last night. Chin-Chin my dear friend."

Daniel Radcliffe, who starred alongside Griffiths in the Harry Potter movies and later on stage with him in "Equus," said he was "proud" to have worked with the actor.

"Richard was by my side during two of the most important moments of my career," Radcliffe said Friday.

"In August 2000, before official production had even begun on Potter, we filmed a shot outside the Dursleys', which was my first ever shot as Harry. I was nervous and he made me feel at ease," said Radcliffe of the late actor renowned for his sense of humour and large store of theatrical anecdotes.

"Seven years later, we embarked on 'Equus' together. It was my first time doing a play but, terrified as I was, his encouragement, tutelage and humour made it a joy."

Born in North Yorkshire, the much-loved British actor’s portly stature made him instantly recognizable on screen.

He gained widespread fame as the irritable Uncle Vernon in the Harry Potter movie series and enjoyed a long career playing bit parts in television series and major movies including Chariots of Fire.

But it was on stage where the character actor excelled.

Griffiths was feted for his portrayal of charismatic teacher Hector in Alan Bennett’s play "The History Boys" – a part that earned him a Tony Award in New York and a Laurence Olivier Award in London.

National Theatre artistic director Sir Nicholas Hytner, who directed the play, described Griffiths’ performance as a “masterpiece of wit, delicacy, mischief and desolation, often simultaneously.”

Griffiths later recreated the role in the 2006 film adaptation of "The History Boys."

In 2012, Griffiths appeared alongside Danny Devito in a West End production of Neil Simon’s comedy "The Sunshine Boys" at London’s Savoy Theatre.

Griffiths is survived by his wife, Heather Gibson.

His agent described him as "remarkable man and one of the greatest and best-loved actors."

With files from The Associated Press