A PERVERT teacher was caught when a classroom assistant spied his child pornography collection on his computer during a lesson.

The Little Heath School assistant reported supply teacher David Armstrong, 63, who was found to have around 4,500 indecent images and videos on two laptops and an external hard drive - more than 300 of which were in the two most serious categories, with some involving children as young as two.

Armstrong was given a 12-month jail sentence suspended for two years at Reading Crown Court on Friday for each of five charges of making indecent photographs or pseudo-photographs of a child between 2007-10, which he admitted at an earlier hearing. The court heard he realised he was attracted to children in his 20s.

Judge Mary Jane Mowat said: "This was by any standards a substantial collection, with some 300 of the worst kind. You are 63 and this is your first conviction despite working as a teacher for 40 years. I don't criticise you for being attracted to children, many very good teachers are, but keep their urges under control."

The judge placed Armstrong on the Sex Offenders Register for 10 years, with a Sexual Prevention Order which bans him from owning a computer or device capable of connecting to the internet, and ordered him to pay £500 costs and undergo treatment. He is also automatically banned from working with children.

The court heard Armstrong, from Devizes, Wiltshire, was arrested in May last year -two weeks after joining the Tilehurst school - after the assistant spotted sinister file names, including 'rape wife', 'nude model' and 'gay alligator', on his laptop computer.

Defence counsel Robin Shellard said Armstrong, who is married and is the main carer of his elderly mother, worked at many schools and colleges and has an impeccable record.

He said some of the pictures were not of real youngsters but of "Japanese images depicting children" and only 0.5% were at the most serious level 5.

After the case, Little Heath headteacher David Ramsden stressed the offences do not relate to any pupils at the school past or present.