AN investigation has been launched after confidential records of cancer patients at the Royal Bolton Hospital were discovered on a computer memory stick.

Estate agent Dawn Rozell discovered the records in the machine after she bought it from a supplier in Crewe.

The computer contained the details of 13 cancer sufferers, their dates of birth, home addresses, telephone numbers, family medical histories and GP details.

Today -- as a patients' group said it was "absolutely horrified" that such information had leaked out and the UK's largest cancer charity said it was "very alarmed" -- health chiefs at the Bolton hospital said they were probing the "security leak".

Miss Rozzell, aged 31, from Crewe, Cheshire, bought the £30 memory stick -- which increases the size of a computer's memory -- from a small, local supplier in her home town.

When she connected it to her laptop, she said she was stunned by what it contained.

"I was astounded," said Miss Rozzell, who runs two estate agent shops in Shropshire. "I just could not believe what I was looking at."

She claims on her computer were "private and confidential" records from the Royal Bolton Hospital.

A spokesman for the Royal Bolton Hospital said: "We are very concerned indeed about this apparent breach of patient confidentiality. We are carrying out an immediate and thorough investigation into how it could have happened. We have told the lady who found this information of this and are working with her. She has assured us that details of patients on the files will not be divulged."