MARRIED men using the services of prostitutes can expect a visit from police officers searching for clues to the disappearance of a teenage vice girl.

Rachel Wilson kept in daily touch with her mother and her grandparents but vanished four weeks ago today.

Cleveland Police, who are becoming increasingly concerned about the 19-year-old, revealed yesterday that any of her customers who have failed to come forward voluntarily to help, can expect a knock on the door.

Detective Sergeant Andy Greenwood said: "We are in possession of information which is going to lead us to people who used Rachel as a prostitute.

"Other prostitutes have given us information about people who regularly use vice girls in the Middlesbrough area."

About 450 posters have been put up around Middlesbrough in the hunt for Rachel, concentrating on shops, cafes and pubs in the Woodlands and Southfield Road areas of the town, where Rachel plied her trade.

A known drug addict, she is the third woman to disappear from the streets of Middlesbrough.

The remains of Vicky Glass, 21, were found on the North York Moors two years ago - her killer has not been caught - while there is still no trace of teenager Donna Keogh, who disappeared from the town in 1998.

Detective Superintendent Tony Hutchinson, the force's senior investigating officer, said they were keeping an open mind about a link between Rachel's disappearance, and those of Vicky and Donna.

He revealed that other prostitutes are concerned about Rachel's disappearance and are actively helping police.

He said yesterday: "We are still following a number of lines of inquiry, but the more time that passes, our levels of concern increase. It is almost four weeks since Rachel had any contact with her family and that is completely out of character.

"We still need information and I would ask people, be they prostitutes or their clients, to come forward and help us. There have been a number of reported sightings of Rachel but, when checked, they have turned out to be mistaken."

Anyone who can help the investigation has the choice of ringing the incident room on (01642) 303187, or speaking directly to Mr Hutchinson on a dedicated mobile phone, 07740 070 624.