The actor, best known for playing ‘Dirty’ Den Watts on the BBC soap, died on Friday morning, just days after being taken ill.
A statement issued by his representative on Friday afternoon read: “We formally announce the loss of Leslie Grantham, who passed away at 10.20am on the morning of Friday 15th June 2018.
“His ex-wife and sons have asked for their privacy to be respected at this difficult time, and for there to be no approaches to them for information or comment.
“They will not be making any statements to the media. They also ask that no photographs be taken of them in their grief.
“There will be a private funeral which will be attended by close family and friends only.”
On Tuesday 12 June, Leslie’s publicist had said the actor was “very poorly” and being cared for by medical staff.
Leslie began his acting career after spending a decade in prison for murder.
He was given a life sentence in 1967 after killing a taxi driver, Felix Reese, during a botched robbery in West Germany.
During his time in jail, he learned how to act and put on shows for his inmates.
He was released after serving 10 years of his sentence in 1977, and quickly enrolled in drama school, with his first mainstream role following in 1984, when he played one of Davros’ henchmen in a ‘Doctor Who’ serial.
The following year, he was cast as Den Watts in the BBC’s new soap, ‘EastEnders’, and appeared in the very first scene.
His character’s time on the show went down in history, with his most memorable storyline seeing him deliver divorce papers to wife Angie on Christmas Day 1986, which a record 30 million people tuned in to see.
After Leslie quit the soap in 1989, Den was killed off when he was shot by a mystery assailant, with his body ending up in the canal.
However, he made a shock return from the dead in 2003, when it was revealed Den had survived being gunned down and had spent the previous 14 years living in Spain.
Leslie left the show again a year later following a real-life sex scandal, and his character was killed-off for good during a showdown with wife Chrissie.
Other roles of Leslie’s include guest roles in ‘The Bill’, ‘Heartbeat’ and ‘Wycliffe’.
He also appeared alongside Melinda Messenger on the Channel 5 gameshow ‘Fort Boyard’ from 1998 to 2001.
In 2010, he moved to Bulgaria to film soap ‘The English Neighbour’, and remained in the country until recently when he fell ill.
Leslie is survived by his three children, Spike, Jake and Danny, and ex-wife Jane Laurie, who divorced in 2013, after 31 years of marriage.