The cause of death of Robbie Coltrane, the larger-than-life Scottish actor who played the beloved half-giant Hagrid in the Harry Potter films, has been revealed.

Coltrane died a week ago at the age of 72 following multiple organ failure, according to multiple UK reports.

The death certificate of the Scottish star also noted he had suffered from sepsis, lower respiratory tract infection and heart block.

Coltrane, who also starred as a Bond villain and in the 1990s British TV series Cracker, had also been diagnosed with obesity and Type 2 diabetes.

His agent of 40 years, Belinda Wright, confirmed Coltrane’s death just over a week ago. She thanked the medical staff at Forth Valley Royal Hospital in Larbert, near Falkirk in Scotland for their “care and diplomacy”.

“Robbie was a unique talent … He will probably be best remembered for decades to come as Hagrid in the Harry Potter films,” she said.

“A role which brought joy to children and adults alike all over the world prompting a stream of fan letters every week for over 20 years.

“James Bond fans write too to applaud his role in GoldenEye and The World Is Not Enough.

“For me personally, I shall remember him as an abidingly loyal client as well as being a wonderful actor, he was forensically intelligent, brilliantly witty and after 40 years of being proud to be to called his agent, I shall miss him.”

Harry Potter author JK Rowling led the tributes on Twitter, writing: “I’ll never know anyone remotely like Robbie again.

“He was an incredible talent, a complete one off, and I was beyond fortunate to know him, work with him and laugh my head off with him. I send my love and deepest condolences to his family, above all his children.”

Harry Potter star Daniel Radcliffe called Coltrane “one of the funniest people I’ve met”.

“I’ve especially fond memories of him keeping our spirits up on Prisoner of Azkaban, when we were all hiding from the torrential rain for hours in Hagrid’s hut and he was telling stories and cracking jokes to keep morale up,” he said of the film released in 2004.

Rubeus Hagrid is the Keeper of Keys and Grounds of Hogwarts, the primary setting for the first Harry Potter novels.

Ms Wright called Coltrane a “unique talent” and said he had brought joy to children across the world playing the boy wizard’s monster-loving friend.

“As well as being a wonderful actor, he was forensically intelligent…, brilliantly witty …, and after 40 years of being proud to be called his agent, I shall miss him,” she said in a statement.

Born March 30, 1950, in Rutherglen, South Lanarkshire, Anthony Robert McMillan changed his professional name as a homage to celebrated jazz musician John Coltrane.

He was a gifted comic actor and a star of Britain’s 1980s alternative comedy boom, playing a string of television roles that included regular appearances in The Comic Strip Presents anthology series.

In 1987, he rose to greater prominence starring alongside Emma Thompson in John Byrne’s mini-series Tutti Frutti as doomed lead singer Big Jazza McGlone in a tale of fictional Scots rock’n’roll band The Majestics.

With crime series Cracker in the 1990s, he showed he could also play serious parts.

Scotland’s First Minister Nicola Sturgeon said it was her favourite of his roles.

“Robbie Coltrane, Scottish entertainment legend – you will be hugely missed,” she wrote.

British actor and broadcaster Stephen Fry – a fellow breakout star of the alternative comedy boom – wrote that he had met Coltrane almost exactly 40 years ago.

“I was awe/terror/love struck all at the same time. Such depth, power & talent: funny enough to cause helpless hiccups & honking as we made our first TV show, Alfresco. Farewell, old fellow. You’ll be so dreadfully missed”.

Coltrane is survived by his sister Annie Rae, children Spencer and Alice and their mother Rhona Gemmell.

-with AAP