DETECTIVES were today hoping against hope for a breakthrough at last in a horrific murder case that has had them baffled for more than 30 years.

Barbara Mayo was just 24 when she disappeared while hitch-hiking to Catterick, in North Yorkshire, in October 1970.

The schoolteacher from London had been travelling north to collect her boyfriend's car, but she never arrived at her destination.

Instead the 24-year-old's semi-naked body was found in woodland, near Chesterfield, in Derbyshire.

She had been raped and strangled.

Despite an intensive police inquiry in the immediate aftermath of the murder, her killer eluded justice.

The case has never been closed and in September 1997 new techniques in DNA profiling led to renewed hopes that police would get their man.

However, while the tests allowed them to eliminate some 300 suspects from the inquiry, the killer himself was never identified.

But last night, detectives from Derbyshire appeared on nationwide television in a 90-minute special, Britain's Ten Most Wanted Murderers, in a new effort to jog someone's memory and finally bring the murderer to the dock.

"We are very much hoping to get some new information out of this," said a spokesman yesterday.

"It has now been more than 30 years since Barbara was killed and our files are still open and will remain so until we have found the man responsible."