A POLICE chief investigating the murder of a woman 27 years ago is 'convinced' someone knows the identity of her killer.

The body of Manchester prostitute Maria Requena was found by two young anglers at Pennington Flash Country Park in Leigh in January 1991 after it had been hacked to pieces with power tools and stuffed inside five bin bags, with one of them containing her severed head.

The discovery was made just over two years after Liverpool sex worker Linda Donaldson's body was found less than three miles away on a farmer's field off Winwick Lane in Lowton in October 1988.

This led to detectives considering the same person may have been responsible for both murders.

Martin Bottomley, head of the cold case unit at Greater Manchester Police, said: "I am convinced someone out there knows who killed Maria and we really do need them to come forward and tell us who did it.

"As it stands there are no forensic links between her death and Linda's.

"But we do have forensic material in both cases which we will continue to investigate.

"Without a name to put to the material, and the nature of the women's work in which they would have worked with hundreds of men, it is very difficult to detect.

"If we got a call from someone who said 'it was this person' then a lot of progress could be made in both cases.

"The cases will never be closed and we will not stop until we find out who killed Maria and Linda."

The cold case unit, which was set up in 2004 following the success of similar squads in America, is currently investigating more than 200 unsolved crimes in Greater Manchester.

With the advance and development of forensic techniques, it is becoming increasingly more likely for detectives to crack historical cases.

Mr Bottomley added: "We do get people ringing us up regularly even without appeals.

"They might be talking to someone about something slightly unusual they remember in the past which prompts them to call us.

"I would urge anyone who has had thoughts like this to get in touch with us."

If you have any information about either of the crimes contact the cold case unit on 0161 856 5961, or the independent charity Crimestoppers, anonymously, on 0800 555 111.