THE mother of the Yorkshire Ripper's last victim has called for a full inquiry into claims that a former police officer's hoax allowed the murderer to carry on killing.

Twenty-year-old student Jacqueline Hill, from Middlesbrough, was found battered to death on November 17, 1980, on waste ground in Leeds.

Her mother, Doreen, said her daughter might still be alive if police had not searched for a hoaxer from the North-East.

At the height of the Ripper inquiry, West Yorkshire Police were sent three letters and an audio tape from Wearside from a man claiming to be the serial killer.

They were convinced the Ripper was from the North-East, so switched the main focus of their inquiries to the region for 18 months.

During that time, Peter Sutcliffe was interviewed and allowed to go free several times, partly because he did not have a Wearside accent, and he killed three more people, including Ms Hill.

It was revealed last week that the second-in-command of the Ripper inquiry, former Detective Superintendent Dick Holland, had confirmed that the prime suspect for the hoax was a former police officer.

He was born and grew up in the North-East, but was eliminated because three characters of the alphabet, as written in police documents, did not perfectly match those in the hoax letters.

Mr Holland said the rest did, and that during the secret internal police inquiry, his voice was not analysed and his blood grouping -the letter-writer was of a rare blood group -was not determined.

Hundreds of suspects for the hoax were only eliminated after they had supplied handwriting for analysis, recordings of their voice and their blood group details.

For almost 25 years, Ms Hill's mother, who lives in Ormesby, Middlesbrough, has stood firm in her belief that her daughter would still be alive if it was not for the hoaxer's intervention.

Since her daughter's death, she has given up reading newspapers and stopped watching the television news. She was unaware that the prime suspect for the hoax, who became known as Wearside Jack, was a former police officer.

But when told of the latest development, she said: "I am shocked by this. I just find it so hard to believe that a former police officer may have been involved.

"I know there was never a full inquiry. I think there should be.

"I hope it will come out into the open. Whoever it was who did it, they should never get away with it."

In a television interview in early 1981, just after Sutcliffe's arrest for 13 killings, Mrs Hill said the Ripper hoaxer "had a few deaths on his conscience".