DETECTIVES are using the latest forensic techniques in a bid to solve hundreds of sex attacks going back two decades.

Northumbria Police yesterday launched Operation Phoenix - billed as the first and biggest operation of its kind in the country.

Police have already earmarked 300 unsolved rapes between 1992-97 alone, where they hope to achieve positive results.

Northumbria Police Assistant Chief Constable John Scott said: "Our message to previous offenders who perhaps think they have got away with their crimes is - they haven't."

The operation is jointly run with the Forensic Science Service, the Crown Prosecution Service and REACH, the rape and sex assault advice and counselling service.

The team is re-visiting exhibits from past crimes, so that biological samples, as well as clothing and property from victims and suspects can be sent off for DNA and other forensic analysis.

North Yorkshire Police, where there were 57 unsolved rapes in the ten years up to 2001, said undetected crimes were constantly being reviewed in the light of forensic advances.

In the Durham Police area, there were 27 unsolved rapes out of 467 recorded over the ten years to 2001.

A force spokesman said it was constantly reviewing old unsolved crimes applying the latest in forensic science.