POLICE have relaunched a 15-year-old murder probe in a bid to find the killer of a Nelson mother.

Cheryl Shackleton was found dead in a London park in February 1991.

The 34-year-old had been severely beaten and her handbag was missing.

She was partially clothed and may have been sexually assaulted.

Her body was found by a dog walker in Telegraph Hill Park, Brockley, but she was only identified a month later following an appeal on the BBC's Crimewatch programme.

Detectives still pursuing her killer last night returned to the show, in a bid to prompt new leads after stepping up their bid to track down her murderer.

Police forces across the country are reopening high-profile cases because of recent improvements in crime detection techniques and technology.

A spokeswoman for the Metropolitan police said: "Reviews are done on a regular basis for all unsolved murder cases."

Mrs Shackleton's son, Sean, who was nine when his mother was murdered, met detectives on the programme and was able to ask all about the circumstances leading up to her murder.

Mrs Shackleton had moved to London following the break-up of her marriage to Michael and her son was living with his father in Yorkshire.

The couple had run their own jewellery shop in the Arcade in Colne.

They then set up a stained glass business before the break-up of their marriage, which led to Mrs Shackleton suffering from mental health problems.

She then sold her home in Messenger Street, Nelson, and travelled the country carrying large sums of money.

Mrs Shackleton - who was the daughter of former Pendle councillor Arthur Jeffreys - was last seen in an off-licence in New Cross, London.

She died from shock, haemorrhaging and a ruptured liver along with other injuries, including exposure to the cold, after being attacked in the early hours. Det Insp Des Nelhams, from the Metropolitan Police's special projects investigation unit, said: "We would like to hear from anyone who may have information, no matter how insignificant they think it may be, as it could be the key to solving this murder."

Officers are particularly interested in speaking to three witnesses who rang in anonymously at the time - they may have crucial information even 15 years after the murder.

The first was a woman who called the incident room and said she had seen Mrs Shackleton and a man walking into the park at about 12.15am.

The second was a woman who called on February 5 and gave a possible sighting at 1.15am. She said she had seen a man and woman in Endwell Road, near the park, and overheard them discussing Paris, where Mrs Shackleton had recently travelled.

The third was a woman known as Lucy who called the incident room in response to an appeal the month after the murder. She said her friend had seen Mrs Shackleton in Endwell Road at about the same time as the second witness. Mrs Shackleton is believed to have carried most of her possessions in a suitcase, which was never traced.