British police investigating the deaths of three prostitutes whose bodies were discovered in the last nine days said yesterday two other sex workers were missing, as fears grow that a serial killer is on the loose.

Senior officers warned prostitutes to stay off the streets after the naked bodies of the three women were found within miles of each other near Ipswich, eastern England.

A local businessman offered a £ 50,000 reward to help find the killer.

On December 2, police discovered Tania Nicol, 19, in a stream near Copdock Mill and on Friday police divers recovered the body of 25-year-old Gemma Adams in the same stretch of water two miles away.

Ms Nicol, who went missing on October 30, and Ms Adams, who vanished on November 15, were friends and worked in the same red light area. On Sunday, an unnamed 24-year-old woman was found dead by a member of the public in the Nacton area of the town.

"This is a deeply disturbing development, particularly in the light of the two murder investigations which have been launched during the past fortnight," said Detective Chief Superintendent Stewart Gull of Suffolk Police.

"While we can't formally link the discovery of the body at Nacton with the two murders, the facts speak for themselves," he told reporters.

Detectives said all three women worked as prostitutes but none was thought to have been sexually assaulted.

Police said two other prostitutes had been reported missing since news of the murders broke and appealed for them to make contact.