Actress Anita Dobson, famous for playing Angie Watts in EastEnders in the 1980s, is joining The Bill.
Anita Dobson will play "tough" mum Lynne in The Bill
The 55-year-old will play the mother of maverick police detective Phil Hunter in the long-running ITV police drama from next month.
Dobson, who is married to Queen guitarist Brian May, played the Queen Vic landlady in EastEnders from 1985-8.
She always ruled out a return to the BBC One soap and her character died off-screen in 2002.
Dobson will play a "tough, no-nonsense woman" in the ITV drama, which has been running since 1984, a spokeswoman for the show said.
"She finds out Phil's making a mess of his life and comes to sort him and his brother out."
The actress will join two other former EastEnders cast members who are now in The Bill - Todd Carty, who played Mark Fowler, and Roberta Taylor, who was Irene Hills.
Explaining her decision not to return to EastEnders, Dobson said: "Why tarnish the gorgeous creation that was Angie Watts?"
Since leaving Albert Square, she has had a guest role in Casualty and been seen in the recent stage production of musical Thoroughly Modern Millie.
Her on-screen husband Den, played by Leslie Grantham, made a high-profile EastEnders comeback after 14 years' absence in 2003.
But in February, Den Watts was murdered by wife Chrissie in the Queen Vic.