Police have arrested seven people following the discovery of a body in a well by gardeners at the grounds of a private house in Audley Drive, Surrey.
The body is still in the well and marine diving teams will attempt to retrieve it later on Saturday intact, to preserve forensic evidence.
A local resident, who did not want to be named, said: "It is really shocking. You do not expect it here. It is a really quiet well-to-do-area."
Police said the size and appearance of the body suggested it was a white male adult.
Officers were called to the scene on Friday after gardeners discovered the body partially submerged in water.
A detective stated that the body remained in the well and the recovery operation was a slow procedure.
"As you can imagine bodies can be pretty delicate things so it will be a fairly lengthy operation," a Metropolitan Police spokesman said.
Detective Chief Inspector Cliff Lyons confirmed: "It is a murder investigation.
"As far as I am concerned, when a body is found in a well, it either fell in there, or was placed in there, and the evidence is apparent that the body was placed in there.
"The body presents a number of logistical challenges.
"The well is two feet in diameter, it is seven feet deep to the water line, and the water is approximately four feet deep," he added.
"We need a police marine diving team, with breathing apparatus, and we need to recover the body intact to preserve forensic evidence.
DCI Lyons declined to speculate on how long the investigation might take, but said it was not going to be a fast recovery.
"It is not possible to ascertain with accuracy the gender of the body but, judging by the size, it is most likely to be an adult, not a child. The person is white."
He appealed for anyone who had concerns about a person who has gone missing, especially if they had connections to that area, to come forward.
A post-mortem examination will be held in due course. Anyone with information is urged to call police on 020 8721 4961 or Crimestoppers anonymously on 0800 555111.