A man on trial for murdering a young woman 15 years ago was tracked down because of advances in DNA technology, a court has been told.

Avril Dunn, 26, was beaten to death in woods close to her home in Luton, Bedfordshire, on 15 September 1985.

Duncan Jackson, 37, from Luton, is on trial at Reading Crown Court, where he denies a charge of murder.

Christopher Hotten, QC, prosecuting, said there were semen stains on Mrs Dunn's clothes but it was not until the 1990s that DNA technology had advanced to the stage at which a sample could be recovered.

Mrs Dunn had been strangled and had suffered massive chest injuries, consistent with someone stamping on her.

Mr Hotten said: "In 1985 identification by DNA analysis was in its infancy. Technology available to forensic scientists did not enable police to determine whose semen was on her clothes."

He said the murder remained "unsolved, but not forgotten" and the exhibits and witness statements were preserved in the hope that further investigations or a scientific breakthrough would enable police to identify the killer.

Mr Hotten said the incident room was reopened in 1998 after scientists extracted a DNA sample from the clothes.

Mr Jackson, a suspect at the time of the killing, was immediately arrested and subsequently charged with Mrs Dunn's murder.

The jury heard that Mr Jackson and Mrs Dunn knew each other and both regularly played darts in their local pub, The Heron.

Mrs Dunn was last seen alive at 2305 GMT on 14 September 1985.

Mr Jackson, who was working as a roofer at the time, told police he left at the same time and went straight home.

But Mr Hotten said police searched a shed in the village of Sundon and found traces of bitumen which matched black marks found on Mrs Dunn's body.

Detectives also found a bone-handled knife in the shed, which matched knife marks on Mrs Dunn's T-shirt, said Mr Hotten.

The prosecutor said the couple went to the shed after leaving the pub and he added: "Something went wrong in that shed and Mr Jackson attacked her. His attack was ferocious and he killed her."

The trial continues.