TEN unsolved murders are being re-investigated by 'cold case' detectives, the MEN can reveal today.

They include a bid to identify the brutal attacker who raped and then battered to death Manchester 17-year-old Dorothy Leyden 38 years ago.

Her body was found in Collyhurst in the early hours of April 25 1971. Advances in DNA analysis have meant that scientists have been able to build up a profile of her possible killer from samples taken from the crime scene.

These have been kept in the basement of GMP headquarters at Chester House until experts were able to extract the vital evidence. There has not yet been a match but further tests are being carried out.

Dorothy's sister Jill Hopkins said last night that the memory of her death 'never goes away'. She said: "All we want is for someone to come forward and say something to help. We want someone to have a conscience".

Officers from Greater Manchester Police's Cold Case Review Unit assessed 150 unsolved murders going back 40 years before selecting ten to focus on. Others cases may be scrutinized again at a later date.

The move follows extra funding from the government.

Former Det Supt Martin Bottomley, in charge of the unit, said: "We are looking at these cases because of advances in DNA data and technology which gives us potential to re-examine evidence in conjunction with the forensic science service.

"We don't forget, we hold the records, we hold the samples.

"Funding is being provided by the Home Office to kick start this process. They have allowed us to re-examine a certain number of exhibits from each case and if there's potential to reinvigorate the case then we will put some of our money in and they will put some of their money to review the whole case.”

Mr Bottomley's team are not only relying on science for breakthroughs. He said they are looking at gangland shootings of young men and boys which are notoriously difficult to detect.

"In gang shootings affiliations will change all the time as gang members change sides. Some will get in trouble for something else and want to do some plea bargaining.

"There may be some changes through love interest. A girlfriend who may have provided an alibi previously may have moved on, or matured enough to realise justice needs to be done."