Members of the public could hold the key to catching a Bradford park sex attacker, police said today.

Detectives believe passers-by around Wibsey Park may have seen the culprit moments before or after he carried out the brutal early morning assault.

A 50-year-old woman was walking her dog there when she was grabbed from behind, forced into a bush and subjected to a serious sexual assault at around 6.25am on Tuesday.

Yesterday she returned to the scene with detectives to retrace her steps. Scenes of Crime Officers had already scoured the spot for potential clues.

Detective Inspector Rob Sumner, who is heading the case, explained that because she was set upon from behind, the victim had been unable to provide a description of her attacker.

"It may be that the key lies with someone who was in the area at the time and saw the attacker. At that time of morning there could have been other people walking dogs or on their way to work," he said.

He appealed for anyone who was in or close to the park - bordered by Wibsey Park Avenue, Reevy Avenue, Beacon Road and Reevy Road - around the time to contact detectives.

"We would like to hear from anyone who saw the woman's black Labrador dog which was left wandering in the park when she was attacked."

He said specially-trained detectives had been speaking to the woman for much of yesterday and she had returned to the park with them to retrace her steps.

"She is obviously in a traumatised state and is being supported and cared for by members of her family," added Det Insp Sumner.

Officers are keen to trace the owner of a dark, Sierra-type car seen at the park entrance at around the time. They said it may or may not be involved.

At least one person has contacted detectives since the Telegraph & Argus revealed the attack yesterday.

Det Insp Sumner said there was no evidence to link the attack to an incident in Wibsey Bank, Odsal, at 2am on Saturday. A 28-year-old woman was grabbed from behind but her attacker fled when a car drove past.

Ring (01274) 376459 if you can aid the police.