A 53-year-old internet pervert has admitted a string of child sex offences after an undercover police operation.

A male police officer posed as a 13-year-old boy to gather evidence against Robert David Coleshill and infiltrate his online chat room.

Coleshill, of Rookwood Close, Uckfield, pleaded guilty to eight charges of gross indecency and attempted gross indecency at a hearing at Birmingham Crown Court today.

He also admitted a further eight counts of being in possession of indecent images of children.

Sentencing was adjourned for reports until January 18.

Detective Inspector Darren Brookes, head of West Midlands Police's paedophile unit, said Coleshill came to their attention following a complaint from a member of the public.

"We were informed that a person was actively seeking out children under age," he said. "We set up this operation, which was the first of its type in Britain, to identify him.

"An officer, posing as a 13-year-old boy, was able to infiltrate Coleshill's internet chat room."

Officers found that Coleshill was "targeting children in the West Midlands with pornography and indecent acts".

These included "sending them web cam pictures of himself committing acts of gross indecency".

Mr Brookes added: "We were able to gain substantial evidence relating to the sex offences he was committing."

He said Coleshill's personal computer was seized and about 500 pornographic images were found, many featuring children under 16.

He added: "Paedophiles mistakenly use the Internet believing that they can remain anonymous, free from prosecution and carry on this sort of vile behaviour without fear of detection or arrest."