Emma Chambers, star of The Vicar Of Dibley and Notting Hill, died of a suspected heart attack, according to a friend.
She passed away aged 53 on Wednesday but her death from natural causes was only announced yesterday.
This morning BBC executive Producer Jon Plowman claimed the specific cause of her death was a heart attack.
He told Radio 4 this morning, saying: "It's no age to have a heart attack, as I understand it."
Plowman, who produced the Vicar of Dibley, added: "Emma was a gifted comic actress who made any part she played look easy. She was adored by the cast and crew."
Social media was awash with tributes from former colleagues and fans. Hugh Grant – who starred opposite Miss Chambers in Notting Hill – wrote on Twitter: "Emma was a hilarious and very warm person and of course a brilliant actress. Very sad news."
Dawn French paid tribute to her former comedy co-star, saying: "Emma was a very bright spark and the most loyal and loving friend anyone could wish for. I will miss her very much."
Emma Freud, the partner of Richard Curtis who wrote both The Vicar Of Dibley and Notting Hill, described her as a "sweet, funny, unusual and loving' human being".
She added: "How could you not love this girl?"
Born in Doncaster and married to fellow actor Ian Dunn, Chambers won warm reviews for her portrayal of Charity Pecksniff in the 1994 TV adaptation of Charles Dickens's Martin Chuzzlewit.
But it was her starring role alongside Dawn French in the hit BBC sitcom The Vicar Of Dibley which earned her national recognition. Chambers played the dimwitted but lovable Alice Tinker, who was an unlikely confidante of the Rev Geraldine Granger.
One of the show's most successful running gags was Tinker's inability to understand any of Granger's jokes which typically closed each episode.
Chambers proved an instant hit with viewers and in 1998 she won a British Comedy Award for Best Actress.
Paying tribute to the star, producer Plowman added: "I think the thing I'll miss most was her laugh."
"She was a very, very good comic actress and she was very bright. Alice appears to be potentially a bit stupid, but she wasn't stupid. Alice just lived in another world and Emma was wonderfully capable of taking us to that other world and playing it very sincerely.
"She was a very good and gifted comic actress."
Fans of the show last night paid tribute. One wrote:
"Thanks for all the giggles", and another added: "This is so shocking and sad. Ah God she was so marvellous."