He starred in the soap between 1985 and 1989, before making a high-profile comeback in 2003
The British actor Leslie Grantham has died at the age of 71.
He was best known for his role as 'Dirty' Den Watts in the long-running BBC soap opera EastEnders.
It had been reported earlier this week that he was in a critical condition in hospital.
A statement from his representative says there will be a private funeral which will be attended by close family and friends only.
Grantham starred in EastEnders between 1985 to 1989, with his villainous 'Dirty' Den Watts becoming one of the show's best-known characters.
Despite apparently being killed in his final 1989 appearance, Den made a dramatic and high-profile comeback in 2003.
He continued to star in the show until 2005, when Dirty Den was finally killed off.
Before his acting career took off, Grantham served a 10-year prison sentence for the murder of a German taxi driver while on army service.
After his release from prison, he began his training as an actor.
As well as EastEnders, Grantham also appeared in TV shows such as The Bill, and also was involved in several theatre productions.
He is said to have completed work on the upcoming film The Krays: Dead Man Walking shortly before his death.
Former co-stars were among those who paid tribute to Grantham.
Letitia Dean, who played Den's adoptive daughter Sharon on EastEnders, said: "I have very special memories of working with Leslie and will cherish them always. He and Anita [Dobson] looked after me in my early days and showed me the ropes, always with care and kindness.
"He never failed to make me laugh and I will remember him with love, affection and gratitude forever."
EastEnders star Leslie Grantham dies, agent confirms/Absolutely gutted to hear this - I remember my early days in @bbceastenders & thinking he was such a strong role model for anyone going in playing a villain great actor v natural which is the key https://t.co/q8bpiPO7AM pic.twitter.com/BXBo9DUxwc— Craig Fairbrass (@craigfairbrass) June 15, 2018
Deeply saddened by the death of Leslie Grantham. I was his agent for many years and he was a kind, talented and charming man. Yes, troubles there were a few, but I shall always remember him with fondness, affection and a smile. RIP Les x.— Michael Whitehall (@fatherwhitehall) June 15, 2018
Statement from Gillian Taylforth on Leslie Grantham's passing: "I’m deeply saddened to hear the very sad news. I have so many happy memories of working with Leslie, he was always great fun and we shared many laughs." 1/2— EastEnders Press (@EastEndersPress) June 15, 2018