Student Jack Tims created a facebook page titled: 'If 2 million people join this group I will give back Maddie McCann.' Photo: PA

Jack Tims, 17, caused outrage after he was revealed as the man behind a Facebook page titled: "If 2 million people join this group I will give back Maddie McCann."

Other users posted comments on the page accusing Madeleine's parents Gerry and Kate of being responsible for her disappearance.

A web campaign eventually succeeded in getting the page shut down.

Mr Tims has now admitted that it was a "stupid, naive" prank which got out of hand, and that he never meant to hurt Kate and Gerry McCann, whose daughter vanished in 2007 aged three.

"The page was meant to be a joke between myself and friends," he wrote in the letter seen by the Kentish Gazette.

"It has since hit home exactly what effect this page may have had on you and your family. I can't imagine what you went through and felt ashamed that I may have distressed you further.

"I wish I could turn back the clock [ ...] I am sorry."

The McCanns' spokesman Clarence Mitchell had said: "There is constant activity by these ghouls. They have accused Kate and Gerry of child neglect and worse, and covering up Madeleine's death.

"The trouble is that it is very hard to stop these people. They hide away behind their computer screens, blogging away."

The revelation follows the jailing of Sean Duffy, who admitted posting videos and messages mocking dead girls.

Duffy was also given a five year Anti-Social Behaviour Order and was prohibited from accessing websites including Facebook, Twitter, YouTube, Bebo and MySpace