A scout leader has been jailed for eight months for collecting pornographic images of children, some of them depicting sadism.
Middlesex Guildhall Crown Court heard Stephen Dudley, 40, downloaded more than 12,000 images of children as young as five on his computer.
He was traced via his email address to his home in Welling, south-east London.
Dudley admitted 19 counts of making the images, one of possessing them and another of distributing a picture.
The court heard the defendant came to the attention of officers monitoring illegal online activities when he began file sharing using an email address in his own name.
Judge Simon Smith said there was no indication his interest in child pornography had "impinged" on his 22 year career in the scouts.
He told Dudley: "The reason for that is the courts feel it right to protect, if they can, young boys and girls from becoming inveigled into this trade of using them to make up pictures of them taking part in sex that other people can view.
"The fact remains that if people like yourself didn't pay money to view these
sort of things, it is far less likely this trade would exist."
Speaking after sentencing, Detective Constable Dave Ball, of Scotland Yard's
Paedophile Unit, described the collection as one of the "largest" discovered.
Dudley was also put on the sex offenders register for ten years and banned from working with children for life.