A PRISON officer resigned in shame after police found hundreds of pictures of child pornography at his home.

David George Lamb falsely claimed he was working for a US-based organisation set up to trap online paedophiles.

The reality was that the 53-year-old father was making and distributing the obscene photographs to other likeminded people.

Lamb worked at Deerbolt Young Offenders’ Institution, near Barnard Castle, County Durham, when he was arrested last year.

The police investigation revealed internet conversations in which he claimed to have had sex with a seven-year-old girl.

Lamb also told online friends that he had sex with a ten-year-old, and that he had committed a sex offence against a girl of four.

Details of his sordid secret emerged yesterday after he was due to stand trial on a string of charges relating to indecent images.

Lamb pleaded guilty as the case was about to start, but will still face a hearing to determine the level of his involvement.

He claims he was corrupted while gathering information against child porn websites after joining Safety Ed International in 2002.

Defence barrister Scott Smith said Lamb got “sucked into” the murky world of making and sharing pictures of his own.

Teesside Crown Court was told that the online conversations were merely fantasy, and no charges have ever been brought.

The court heard that while Safety Ed officials did help the police, Lamb’s actions did not lead to a single website being closed down.

Richard Bennett, prosecuting, said police believe Lamb’s involvement in the now-defunct organisation was a “smokescreen”.

“There is no evidence that any websites were closed down as a result of his actions,”

Mr Bennett told the court yesterday.

“The defendant, in the course of his chat with another user, discloses that he has had sexual intercourse with a girl of ten.

“He goes into some graphic detail about what he would do. The prosecution cannot gainsay his claim that it was fantasy.”

Lamb, of Waterloo Yard, Barnard Castle, pleaded guilty to four charges of distributing indecent photographs of children in March last year.

He also admitted 15 charges of making indecent photographs, and one of possessing 565 indecent photographs of children at his former home in Stainton, Barnard Castle, on March 27 last year.

He was ordered to register as a sex offender, and freed on bail ahead of a hearing to determine his level of guilt.