Officers from the Underwater and Confined Space Search Team are attempting to remove the body of an adult from an ornamental well in a garden in Surrey.
Police said the process is likely to take some time as the positioning of the body in the four-foot deep well presents a number of logistical challenges".
Seven men were arrested on suspicion of murder this afternoon and are still being questioned by police.
More top news
Ewan Williamson,14, died from heatstroke in Australia after police took almost an hour to respond to his distress call, an inquest heard.
Explosives and suicide vests have been seized from a group of suspects stopped on Turkey's border with Syria, the Turkish army has said.
The teenager's family spoke of their "torment and pain" after serial killer Levi Bellfield finally confessed to her murder.