The body of a man found in a well in Warlingham was bound up and been there for up to two years, police have revealed.
Officers were called to an address in Audley Drive, at about 1.50pm on November 15, after two gardeners discovered the body in a well.
Specialist officers, including Metropolitan Police divers attended and recovered the body on Saturday afternoon.
A post-mortem examination which took place on Sunday, was inconclusive, but the examination revealed the man had sustained injuries consistent with an assault prior to being placed in the well by a third party.
Detective Chief Inspector Cliff Lyons said: "Our enquiries continue to try and establish the identity of this male.
"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 investigation has so far seen the well where the body was found partly demolished and water from within the well taken for forensic examination.
Police say forensic work will continue on the well, the house and the outbuildings at the property to establish as much evidence as possible.
DCI Lyons added: "While our work continues to establish the facts of how this male came to sustain his injuries and his body end 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 who were arrested on suspicion of murder have been bailed until a date in late December.
Anyone with information is asked to call the incident room on 020 8721 4961 or Crimestoppers anonymously on 0800 555 111.
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