DETECTIVES leading the investigation into one of Britain's most notorious murders yesterday revealed that technological advances could bring them closer than ever to catching the killer.

The body of housewife Ann Heron was found in a pool of blood, in the grounds of her home on the edge of Darlington, almost 15 years ago.

The 44-year-old, who had been sunbathing outside Aeolian House, had her throat slashed. She was discovered by her husband, Peter.

Mrs Heron's killing has led to one of the region's longest murder inquiries, with police adamant that scientific advances could eventually pinpoint the killer.

And yesterday, Durham Police announced a series of fresh developments.

The force has called in one of the country's foremost forensic experts to lead a series of laboratory tests.

Breakthroughs in technology in recent months will allow the expert - who has not been named - and his team to examine samples from the murder scene, which are so small that, until now, they have been beyond scientific analysis.

Detective Superintendent Dave Jones, who is leading the investigation, said: "The experience he brings from the cutting edge of technology could, ultimately, be crucial. He will head the team based at the Home Office's forensic science laboratories in Wetherby, and will be looking at a range of samples and exhibits, some of them so minute they have never been examined. I hope to have results before the end of the year."

Police have also produced a 3D computer reconstruction of the house and grounds.

A South Yorkshire-based company was commissioned to reconstruct Aeolian House, using all available material, including the video footage and photographs taken on August 3, 1990 - the day Mrs Heron was killed.

Det Supt Jones said: "We added all the information that has since been discovered by the inquiry team, including the location of the body, blood traces and individual fingerprints.

"The reconstructed scene has been used to test theories on what might have happened in the moments immediately before and after Mrs Heron's death. That work has provided fresh impetus and important lines of inquiry."

A report by retired detective Ian Phillips, who was brought in last year to lead a "cold case" review of the murder, is also due to be completed shortly.

Over the past year, Mr Phillips has read hundreds of statements, examined thousands of samples and looked at files on more than 100 suspects.

Last night, he said: "I think we're nearly there. There is genuine hope and we just have to keep going.

"The virtual reality taking us back 15 years and allowing us to look round the scene is something I never thought I would see.

"If it's ever going to happen, it's going to happen now - I long for the day that I get the phone call to say it has."

Talks with the Crown Prosecution Service are ongoing.

Det Supt Jones said: "We do remain absolutely determined to bring the person responsible to justice."