Police hunting the killer of five prostitutes said tonight they were tightening the net around a series of suspects.
Annette Nicholls
They refused to reveal how many individuals were in their sights for the Suffolk murders but sources suggested that the number was less than 50 — not all of them men who used prostitutes.
Police said a "number of interesting lines of inquiry were being followed".
"There are a number of people of interest to us," said Detective Chief Superintendent Stewart Gull.
"We are making good progress and are pursuing a number of interesting lines of inquiry."
Mr Gull added: "We have got a range of individuals who have been suggested to us. Some are local and some are not. Some are not punters.
"We are determined to find the person or persons responsible."
Earlier, detectives confirmed that the fifth woman found dead near Ipswich in the past two weeks was missing prostitute Annette Nicholls, 29.
Despite a post-mortem examination the cause of her death was not clear and further tests are being carried out.
Four other women have been found dead in villages near Ipswich in the past fortnight.
Gemma Adams, 25, was found in Belstead Brook at Hintlesham on December 2. Miss Nicol was found in the same stream at Copdock on December 8.
They were naked and their bodies had partly deteriorated in the fresh water. Detectives have not revealed the cause of their deaths.
Anneli Alderton, 24, was found in woods at Nacton on December 10. She, too, was naked and had been strangled.
Paula Clennell, 24, and Miss Nicholls were found naked in woods at Levington on Tuesday.
More than 300 officers — from more than 20 forces — are hunting one of the biggest serial killers in British criminal history.
Meanwhile, Suffolk Police said tonight they were investigating a report that a girl had gone missing.
A spokeswoman said officers had been told that the girl had gone missing with her boyfriend.
The spokeswoman said it was too early to say whether the incident was linked to the investigation into the murder of five Ipswich prostitutes.
"We do have a report of a missing girl in Suffolk," said the spokeswoman.
"But we also understand that the girl's boyfriend is missing."