Police have issued a fresh appeal for information about what happened to Charlene on the anniversary of her disappearance in Blackpool.

In the years since she went missing, police have uncovered evidence that Charlene had been the victim of child sexual exploitation after being groomed by a gang.

She was last seen after saying goodbye to a friend late at night near an alleyway in the Lancashire town.

On the anniversary of her disappearance, her mother Karen described Charlene as a "bubbly, cheeky teenager with an infectious smile" who loved animals and music.

She appealed for help from the community: "All we want is answers. Obviously somebody out there knows something and we want somebody to come forward and please end our nightmare.

"After 20 years it is terrible. We just live in hope, we hope and pray that something will happen and we can get justice or closure for Charlene."

Charlene's father Bob said the last 20 years had been "very traumatic" for the family.

A year after Charlene disappeared, information was passed to police that led to the launch of a murder inquiry.

Two men were charged in connection with Charlene's murder but a jury was unable to reach a verdict. A retrial later collapsed.

Prosecutors had claimed during the case in 2007 that Charlene's body had been dismembered and disposed of at a kebab shop in Blackpool.

Lancashire Police faced criticism over its handling of the case following an investigation by the Independent Police Complaints Commission, the body subsequently replaced by the Independent Office for Police Conduct.

The force continues to have a dedicated team conducting what it says is one of the largest investigations in its history.

Det Chief Supt Pauline Stables, the force's head of crime, told Sky News: "I think it is really important that we never give up hope.

"There's got to be somebody out there who knows what's happened and now's the time to come forward and tell us.

"You may be in a position where at the time you didn't feel strong enough to come forward, there might be reasons of your own vulnerability that you couldn't come forward and tell us.

"Twenty years on, we hope that now is the time for those people who have got answers to tell us. It is not too late."

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Charlene was captured on multiple CCTV cameras in the hours before her disappearance, the last image was of her smiling in a restaurant on the pier.

Police say the investigation into her disappearance has generated nearly 16,000 lines of inquiry in the last 20 years.

A reward of £100,000 remains on offer for information leading to the prosecution of her killer or the recovery of her body.