UNSOLVED rape and sexual assault cases in Lancashire over the last 30 years are to be reinvestigated using the latest DNA techniques.

Lancashire Constabulary has launched Operation Goldcrest to hunt down predatory and violent offenders who have slipped through the net.

The force has set up a cold case' review team to look into historical cases dating back over three decades.

Small pieces of DNA which were previously not enough to trace offenders will not be re-examined using modern technology.

An initial 70 cases committed out in Lancashire between 1984 and 1999 have been identified for new examination using the latest technology.

Goldcrest is being run jointly by the Major Investigation Team and the Forensic Science Unit based at police headquarters in Hutton.

Victims will not be contacted until a DNA match identifies a suspect, so that their hopes are not raised unnecessarily.

Det Chief Inspector Andy Webster said: "The cases under review are amongst some of the most serious sexual offences committed in Lancashire over the last 25 years.

"It is important that the people who have committed these appalling crimes are brought to justice.

"We want to put the fear of crime back on the perpetrators of crime.

"My message to them is simple. One of these days we will come for you".

Advances in DNA technology have been highlighted after Ronald Castree was jailed for the murder of 11-year-old Lesley Molseed, 32 years ago in West Yorkshire.

Castree was arrested after a DNA sample that had been taken in connection with an incident in 2005 matched a sample found on Lesley's underwear.

The evidence exonerated Stefan Kiszko, who mistakenly spent 24 years in jail for the crime.

The technology was also used to catch Blackburn's Witton Park rapist, who carried out a horrific 90-minute sex attack on a 22-year-old woman walking her dog in 1995.

DNA evidence linked 54-year-old lorry Graham Darbyshire, of Elm Grove, Cuerden, Leyland, to the crime and to a similar attack in Boothstown, Greater Manchester, in 1993.

The Witton Park case was solved 11 years after it happened by Greater Manchester Police's cold case review team.

The work of such teams has prompted a number of TV dramas such as BBC 1's New Tricks, featuring Dennis Waterman.

Lancashire's team will be working in connection with Forensic Science Service, the Crown Prosecution Service, Victim Support Scheme (VSS) and Lancashire's Sexual and Forensic Examination (SAFE) Centre.

It also has a dedicated forensic scientist and CPS lawyer to deal with the cases.