Police today launched an investigation after the parents of a 15-year-old pupil at Boston Spa Comprehensive School found hardcore pornographic images on her school laptop computer.

Jane and Jeffrey Bridges, of Methley, near Leeds, were outraged when they discovered the material, showing explicit pictures of adult couples and lesbians, on a laptop being used by their daughter, Roberta.

They have now handed the laptop to West Yorkshire Police and demanded a full explanation from the school, and Leeds Education Authority.

"It has got to be found out how something so obscene can slip through the net," Mr Bridges said.

"When I opened the My Documents folder I found blue movies and if I can find it on my own, then others can."

He added: "The stuff that's on there is just downright disgusting."

Roberta had been using the laptop during the school day to help her with her work because of a medical condition which forces her to wear a body brace and restricts her ability to write at a desk.

Mr Bridges said the local education authority had provided her with the computer and that the school had later paid for it.

But when Roberta took the computer home and told them that she was sure other people were using it, her parents made their shocking discovery. As they searched the laptop's memory and opened the Temporary Internet Folder, which stores a copy of web page images, they were presented with the graphic pictures.

A West Yorkshire Police spokesman confirmed: "We have taken possession of a computer and investigations are under way."

The council said it was also looking into the incident, which it described as a "cause for concern".

Updated: 15:31 Tuesday, January 23, 2001