Body in Warlingham well: Victim had been tied up
A man found dead in a well had been tied up and his body left there for about two years, police have said.
The body was discovered by workmen at a home in Audley Drive, Warlingham, south London, on Friday.
Post-mortem tests proved inconclusive but detectives say the victim was a white man who had been assaulted.
The incident is being treated as murder and forensic work at the site, on the Surrey border, will continue for about a month.
Det Ch Insp Cliff Lyons said officers were reviewing missing person reports to try to establish the man's identity.
"This is someone's son and my team owe it to him and his family to find out the truth and bring those who committed this atrocious act to justice," he said.
Asked if he thought the man was dead before being put in the well, Mr Lyons said there was "every indication" that was the case.
Police divers took several hours to retrieve the body on Saturday from the water, which is about 4ft (1.2m) deep.
The well has been partly demolished and water taken away for forensic examination.
Mr Lyons said: "The water has lots of insect larvae, property that may have fallen into the well, skin deposits etc that may offer opportunities for forensics and for identification."
Seven men aged between 21 and 27 who were arrested on suspicion of murder have been bailed until late December, pending further investigations.