Sean McQuinn, of Bracken Bank Grove, Keighley, threw memory sticks with 400 child porn images into drain

Sean McQuinn was told by a judge that the offences he had committed against the boy – which were in the presence of another child – were “disgusting”.

Judge Jonathan Rose said the victim was vulnerable and young and 51-year-old McQuinn had seen and taken the opportunity to sexually abuse the little boy.

The judge added: “Your offending against him has had a profound effect. There must be punishment for that.”

McQuinn, of Bracken Bank Grove, Bracken Bank, Keighley, pleaded guilty to three charges of sexually assaulting a male child under 13.

He also admitted seven charges of making indecent images and three of possessing indecent images of children.

Prosecutor Abigail Langford told Bradford Crown Court that McQuinn touched the boy indecently over his boxer shorts while he was sitting in his lap. Miss Langford said the touching took place between 11 and 15 times, during the same incident, on April 5.

The boy disclosed what had happened and McQuinn was arrested the next day. His home was searched and a number of items were seized, including two computer towers and two laptops.

More than 400 indecent images, some of them videos, were found on two memory sticks which had been discarded in a drain.

The moving images included one of a girl aged ten to 13 being sexually abused, and sexual abuse of boys as young as ten.

McQuinn’s solicitor advocate, Andrew Walker, said his client had suffered from alcohol dependency for more than 30 years and the offences appeared to have occurred as a result of his alcoholic intake.

Judge Rose said he agreed with a probation report that McQuinn was at high risk of causing serious harm to children through sexual abuse.

He said the defendant contributed to the sexual abuse of children every time he viewed indecent images of them.

Judge Rose said: “Those evil people who make those images would not do so unless there was a market for viewing such filth.”