A KNIFE, which police believe was used by a rapist to threaten a 17-year-old girl in a park in Bolton, was today due to be examined by forensic experts.

Detectives recovered the blade -- which was held to the girl's throat during her horrific ordeal in Moses Gate Country Park on Tuesday afternoon -- near to the scene.

It is now undergoing forensic tests as the major hunt for the sex fiend continues.

Police have warned that the rapist could strike again and advised women to avoid secluded parts of the park.

Today detectives were shifting through information volunteered from the public following a witness appeal. They said they have been pleased with the response to an appeal in Friday's Bolton Evening News which featured an e-fit of the rapist.

The rape victim was walking her dog in the park at about 2pm when she was grabbed around the waist and threatened with the knife.

The sex attacker took her into woodlands where he ordered her to strip before raping her.

She only managed to escape by running naked through the River Croal and waded to the other side.

Forensic experts completed their fingertip search of the area on Friday and re-opened the secluded track where the attack happened.

Extra police patrols have been drafted into the park, including mounted officers and a mobile police station has been set up until Sunday night.

Det Insp Andy Aston, who is leading the hunt, said: "The response to the e-fit was very good and we are following a number of new lines of inquiry.

"We have spoken to a number of key witnesses and we are following up all the new leads."

Detectives had made a direct appeal for certain witnesses who were believed to be in the park at the time of the attack to come forward.

A woman in her 20s wearing a white coat and pushing a buggy with a two-year-old child has already come forward.

Police would still like to speak to a man in his 70s, with grey hair who was wearing a green jacket and glasses walking a Golden Labrador thought to be called Ben.

The man was sat on a bench between the river and Farnworth Cemetery shortly before the attack and officers believe he may have vital information.

Anyone with information is asked to call Farnworth CID on 0161 856 5853 or Crimestoppers on 0800 555 111.