A BODY discovered in a well in Warlingham had been there for around two years, police have said.
Officers initially said the man, who was discovered by gardeners at the house in Audley Driver on Friday, had been there for around two weeks.
But a post mortem, which found evidence of assault injuries, has confirmed the body, which was bound up and wrapped in a blue tarpaulin sheet, had been there far longer.
Further tests are being carried out as efforts to identify the man continue.
Detective Chief Inspector Cliff Lyons, leading the investigation, said: "These enquiries have included reviewing missing person reports but this process may take some time.
"I would like to thank the public for their positive response to our appeals so far and specifically those in the local community who have been supportive throughout the disruption caused by police and media in their neighbourhood.
"Given the complex nature of this investigation, it is likely that forensic work at the property will continue for a further month as we attempt to secure all available evidence."
The police have partly demolished the well and water has been taken away for forensic examination.
That work will continue, as well as investigation of the house and outbuildings.
Detective Chief Insp Lyons added: "While our work continues to establish the facts of how this male came to sustain his injuries and his body ended up in the well, our focus is also on finding out his 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."
Seven men, aged between 21 and 27, were arrested on suspicion of murder. They have been released on bail until a date in late December.
Anyone with information is asked to call the incident room on 020 8721 4961 or call Crimestoppers 0800 555 111.
