The 42-year-old doctor who posed as a teenage girl and used this false identity to chat online with 26 genuine teenage girls using "indecent language about sex and underwear" was yesterday struck off by a General Medical Council fitness-to-practise panel.

Thomas Dent - a GP and director at the National Institute for Clinical Excellence - "accessed porn websites and swapped photos with youngsters while talking to them in chatrooms about masturbation and orgasms", as we reported yesterday.

Dent was arrested in May 2004 by a special constable who happened to sit next to him on a train while he used his laptop to pose as "Katie Beckinsale" and was spotted "looking at a picture of a teenage girl". He avoided criminal prosection for grooming children, but received a five-year risk of sexual harm order and a civil order.

The GMC ruled Dent unfit to practice. He said: "I'm ashamed of what I did." ®