Sheridan Smith and Stephen Merchant will star in a new BBC drama about the murders committed by Stephen Port.
The Barking Murders will be told from the point of the view of the families of the victims, focusing on their fight to uncover the truth about what happened to their sons and brothers.
The serial killer drugged and raped young men before dumping their bodies near his home in Barking, east London.
The police watchdog is looking at whether any charges of gross misconduct should be brought against officers involved in the initial inquiry which allowed Port to slip through the net.
The three-part factual drama will be written by Jeff Pope and Neil McKay, who were responsible for The Moorside and Appropriate Adult.
Merchant will play Port while Smith will play Sarah Sak, the mother of victim Anthony Walgate, and Jaime Winstone will play Donna Taylor, one of the sisters of victim Jack Taylor.
Merchant said: “This is a story that can’t be ignored – how four young lives were lost and their families’ brave attempt to uncover what happened.
“This factual drama will shed light on their story, so it’s a privilege to be a part of telling it with the brilliant combination of Jeff Pope, Neil McKay and the BBC.”
Smith added: “I love playing real-life characters – especially an inspirational woman like Sarah Sak – but with it comes responsibility.
“Along with the other families, Sarah went through so much heartache and it would have been easy for her to just accept what she was being told by the police, but something inside made her keep fighting for her son.”
McKay said: “Four young men with their entire future ahead of them lost their lives in a brutal and tragic way.
“This is a story not only of the consequences of that loss but also of the extraordinary courage and resilience shown by those who loved them as they sought truth and justice. It is a privilege to be able to tell it.”