Metropolitan police are investigating three alleged murders connected with a supposed Westminster paedophile ring, the force confirmed on Thursday.
No victims have been identified for the murders, which are alleged to have taken place in the late 1970s and early 1980s at various location across London and the southeast.
The inquiry is part of Operation Midland, a wider investigation into allegations of historical child abuse by politicians and other public figures at the Dolphin Square building in Pimlico, London, close to the Houses of Commons.
Police working on the case said they believe the murder claims, based on the testimony of an alleged child-abuse victim known only as "Nick", are "credible and true".
Kenny McDonald, the police officer leading Operation Midland, told the BBC he believed the account and called on more witnesses to come forward: "We are thinking of one premises, though I am not ruling out more. I am looking for people who lived, worked or frequented that building.
"We know from what is being said to us that there were other young boys abused at this time," he added. "I know there are others out there, who I know will be out there. ... I need others to come forward and speak to us. You will be believed, you will be supported, as we look to build this case."
DetSupt McDonald: We are also investigating the murder of 3 young boys - we are determined to find answers #OperationMidland
Detective Superintendent Kenny McDonald leads #OperationMidland - I appeal to men who were subjected to abuse 30years ago to come forward
People lived/visited Dolphin Square 1970s will have seen/heard something that only understand significance of now #OperationMidland
"Nick" claims he was abused a child between 1975, when he was 7 years old, and 1984. He says he was driven to parties at a Dolphin Square flat where he was abused by groups of men, including MPs.
The apartment building, just a mile away from parliament, was a popular residence for politicians and other high-profile individuals.
"Nick" has previously told police he saw a Conservative MP murder a boy, while former police officers were allegedly told not to pursue the group in the early 1980s, according to claims reported by the Sunday People and Exaro News