The cold case unit from Leeds Trinity University has started examining the facts around missing Charlene Downes, who was just 14 when she vanished. No one has ever been convicted in relation to her death or disappearance after she never returned home on November 1, 2003. But police believe she may have been killed by a gang based in Blackpool, Lancs, after finding evidence that she had been groomed for sexual favours.

In 2007, two men were put on trial in connection with Charlene's murder. During the hearing, prosecutors alleged her body had been cut up and minced into kebabs and her bones crushed into tile grouting. However, the jury in the case was unable to reach a verdict about their guilt.

And after a re-trial was scheduled, the accused were released in April 2008 because of concerns about the evidence gathered by Lancashire Constabulary.

Charlene Downes, 14, who went missing from home in Buchanan Street, Blackpool, at the beginning of November 2003.

Now Dr Kirsty Bennett, a lecturer at Leeds Trinity University specialising in cold cases, will lead a new team trying to discover what happened to Charlene. She will work with Ronay Crompton, from the Justice for Charlene Downes campaign, and they hope to find "new evidence" about the teen's disappearance.

Ronay said about the collaboration: "Our main aim is to review Charlene's case and see where the failings are and go out to get new evidence. Blackburn Uni also approached us to undertake large child sexual exploitation (CSE) project for whole of Lancashire to find out the scale of the problem, and where children are being failed.

"Charlene was failed by everyone that should have kept her safe. The police, social services, they all let her down. We're trying to build a legacy and fight for real justice for her, so she can be remembered for something positive."

The body of Charlene, who moved to Blackpool from the Midlands with parents Bob and Karen and brother Robert when she was 10, has never been found. And what emerged from Charlene's disappearance was a worrying picture of child sexual exploitation in Blackpool, which campaigners say hasn't gone away.

Today, there remains a £100,000 reward on offer from the police for information leading to the conviction of Charlene's killer.

A spokesman for Lancashire Police said: "The case remains open and we would appeal for anyone with information to contact us."

A Blackpoool Council spokesperson added: "Tackling any type of exploitation of our young people is a high priority for the council. The Awaken project, which was set up in the wake of Charlene's disappearance, was one of the first teams in the country to combine the resources of the police, social services and health to tackle Child Sexual Exploitation.

"Since it was established in 2003 hundreds of vulnerable young people have been identified and protected from harm and offenders brought to justice."

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