POLICE in Middlesbrough are continuing their investigation into the murder of prostitute Kellie Mallinson and have renewed an appeal for her former clients to come forward.

Superintendent Graham Strange, who is leading the investigation, said yesterday that tests showed the 20-year-old died from asphyxiation.

He said: "We are still seeking help from people who knew Kellie, who may have seen her between 9.30pm on Saturday, September 9, and 11.50am on Sunday, September 10."

He appealed for taxi drivers who may recognise Kellie by her distinctive walk to come forward, or regular customers of Kellie's who may have arranged to see the prostitute at some point during the weekend that she died, to help detectives piece together the last hours of her life.

He also appealed to former clients of Kellie's to come forward so they could be eliminated from police's inquiries, before officers paid visits to their homes.

Supt Strange assured them they had nothing to fear.

He said: "The police here do have quite a vigorous prostitution policy for those involved in kerb-crawling, but this is a murder inquiry and that overrides it."

Supt Strange, who is currently head of operations at Middlesbrough Police, has been head of the force's vice squad for 18 months and feels many people do not understand the complexities of how young women get involved in prostitution.

"In Kellie's case, she was coerced by a young female friend at the age of 15. She was vulnerable and not mature enough to make informed choices, and became involved in prostitution and then drugs," he said.

"She was a 20-year-old girl, a young woman with her life ahead of her, and her life has come to a tragic end. It is a very sad case."

Anyone with information is asked to call the incident room on (01642) 303388.