Paul Nicholls has signed up to join the cast of Law And Order: UK.
The former EastEnders actor will appear in the sixth series of the show, which will air in January next year.
Paul will play a headstrong young officer called DS Sam Casey who is brought in to investigate the shooting of Jamie Bamber's character DS Matt Devlin.
Producers said DS Casey has "a very strong sense of justice".
Paul joins Bradley Walsh, Harriet Walter, Freema Agyeman, Peter Davison and Dominic Rowan in the seven-part series, which sees the police and legal teams facing a shocking crime captured on video, pits them up against the clock in the search for a hostage, and sees them expose a tragic, medical cover-up.
"Cases are reopened, the past threatens to catch up with Ronnie (played by Bradley) and careers are on the line," a show insider said.
Other guest stars joining the cast for series six include Tamzin Outhwaite, Toby Stephens, Eva Pope, Luke Roberts and Tim McInnerny.
The fifth series, shown this summer, attracted an audience of 5.6 million.