GATHERING dust on a police station shelf in North Yorkshire is a gruesome reminder of a 30-year-old mystery.

The sightless eyes of the wax head bear eloquent testimony to an enduring puzzle that baffled some of the best police and forensic minds in the country.

The lifesize bust is the carefully- crafted likeness of a woman whose skeletal remains were found, hidden in a 6ft tall patch of rose bay willow herb, near the top of Sutton Bank on August 28, 1981.

She was found following a telephone tip-off to police in Ripon. The male caller said simply: “Near Scawton Moor House you will find a decomposed body.”

He gave precise directions but refused to give his name, bizarrely citing “national security”.

To this day, he has not been traced.

The discovery of the bones sparked a huge police operation that spread far and wide – even, through Interpol, to other countries.

Veteran detective Strickland Carter, now long retired, headed North Yorkshire’s CID for eight years during which there were almost 40 murders, all of which he solved.

But the mystery of who the Sutton Bank woman was – and how she died – eluded him despite an intense investigation, worldwide publicity and thousands of man-hours.

So thorough was the inquiry that it successfully tracked down 164 women who had been reported missing.

Forensics established the woman was aged between 38 and 40, was 5ft 2in, with dark hair.

She had given birth to probably three children and had a spinal abnormality which would have given her backache.

She had been dead for up to two years.

After reading an article about the successful reconstruction of the face of an Egyptian mummy, Mr Carter contacted the Department of Medical Illustration at Manchester University where, working from the skull, experts created the lifelike wax head.

Hair and make-up were completed by technicians at Granada TV and the finished model was then unveiled to the media.

But although the resultant publicity was huge – for what was then thought to be a world policing first – no one came forward to identify the woman.

Convicted killer Geraldine Elizabeth Crawley escaped from Askham Grange prison near York in 1979 and had a similar description to the dead woman.

But she was ruled out when, following a public appeal, she obligingly wrote to Mr Carter from her hideaway in Ireland, enclosed two samples of her fingerprints and wished him well with the inquiry.

Theories abounded, most prominent of which was that she was a prostitute. Then, as now, Mr Carter had other ideas. “I think it is most likely she was some sort of gypsy,” he told The Northern Echo yesterday.

“Her teeth were in too bad a condition for her to have been able to work as a prostitute and I think she was someone who didn’t have normal access to NHS dental service.”

He added: “The whole thing was very sad and it is still a great disappointment to me that we could never put a name to her.”