Stephen Merchant is to star as Stephen Port in a new BBC fact-based drama about the serial killer who murdered four young men he met through dating websites between 2014 and 2015.

The Barking Murders, which is due to begin filming this spring, will be told from the perspective of the families of Port’s victims as they fight to uncover the truth about what happened to their sons and brothers amid a much-scrutinised police investigation.

Sheridan Smith will play Sarah Sak, the mother of Port’s first victim, Anthony Walgate, while Jaime Winstone will star as Donna Taylor, sister of Jack Taylor. The screenplay will be written by Neil McKay, whose previous credits include the Fred and Rose West drama Appropriate Adult and The Moorside, which dramatised the kidnapping of schoolgirl Shannon Matthews.

Port, now 43, was given a whole-life sentence in 2016 for the murders of Walgate, Taylor, Daniel Whitworth and Gabriel Kovari. Widely referred to as “the Grindr killer” in the media, the former chef met his victims using dating apps and drugged them with lethal amounts of the date-rape drug GHB, before raping them and dumping their bodies near his home in Barking, east London.

Despite the similarities of the circumstances around the men’s deaths, the Metropolitan police initially did not connect the four cases. A police watchdog investigation into the Met’s handling of the case was completed in August ahead of a full inquest this year.

The role of Port marks a significant departure for Merchant, who is best known for his work with Ricky Gervais on BBC comedies The Office and Extras. The writer and actor has also appeared in films including Gnomeo and Juliet, The Girl in the Spider’s Web and the forthcoming wrestling comedy Fighting With My Family.

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.”