A TATTOOED kickboxing instructor has been jailed for 21 years for sexually abusing children in his care over two decades.

David Prosser, 50, ran kickboxing classes across west London, including Northolt Swimarama, Shadwell Drive Community Centre, and Dormers Wells School.

After a victim came forward to police, they uncovered a web of sexual abuse against children aged between nine and 13 who had attended his kickboxing classes.

In some cases, Prosser had offered the children extra tuition in his bedroom of the flat he rented in Hanwell, where he launched further attacks.

The father-of-two was jailed today at Isleworth Crown Court, after being convicted of charges of rape, attempted rape, and sexual assault against 20 boys and one girl between 1980 and 2000.

Prosser lived in Bristol and set up kickboxing classes in Wiltshire, before moving to Hanwell in 1991.

He became a well-known kickboxing instructor across west London, but in 1997 went on trial for sexually abusing two young boys who attended his classes.

He was found not guilty at the trial and returned to Wiltshire, but in 2007 one of his victims contacted police saying he had been abused by Prosser.

Following a lengthy operation by Met officers, where 20 further victims were identified, Prosser was arrested at his Wiltshire home in May 2008.

Cops seized drug paraphernalia, porn films, sex education books for children, lewd playing cards depicting sexual acts, and a vibrating massager.

Prosser initially refused to speak about the allegations when questioned, but later admitted abusing children.

Detective Sergeant Tim Bramley, who led the operation, said after sentencing: "Prosser has spent years perfecting his grooming of young children who looked up to and admired him.

"He manoeuvred himself into a role that gave him access to young boys, giving him the opportunity to work with the boys physically and allowing him to progress from training exercises to abuse.

"When the first victim came to us in 2007 and told us of the abuse he had suffered, officers immediately started to identify and speak to other people who knew him at that time. It felt like every time someone else was approached, another victim was uncovered.

"Many of the victims were speaking for the very first time of the abuse they had suffered; it was a traumatic process for both the victims and the officer. Not all of those people spoken to felt they were able to give a statement to police but everyone was grateful that at long last Prosser would finally be stopped.

"I hope that the conviction of Prosser will give the confidence to other victims of abuse to come forward, they will be listened to, allegations investigated and their wishes respected."

Prosser pleaded guilty to eight count of indecent assault at an earlier hearing, but denied all other charges against him.