Two men who were photographed abusing children were identified after police painstakingly pieced together a large bag of shredded photographs into more than 300 images.
A large volume of the images found at Michael Peter's home in Halifax were indecent images of children of the most serious level.
They also identified Peters, who's 71, and Andrew Bristow, aged 48 and from Normanton, as some of the men assaulting the children. The two were sentenced at Bradford Crown Court to a total of 14 years for rape and sexual activity with children, in the first case to be taken on by the newly formed Calderdale Abusive Images Unit.
The two men were arrested by Calderdale Police in July 2015. This was after a tip off by colleagues from Surrey that a suspect in a local child grooming and sexual offences investigation had sent one text message to Peters of a suspicious nature.
The Abusive Images Unit took on the case and officers recovered a large bag of shredded photographs from Peter's property.
In a lengthy and complex investigation, the team identified a number of children from within West Yorkshire and beyond, all whom had contact with Bristow and Peters. The offending was found to have taken place over a decade ago, between 2004 and 2006.
Police have praised the bravery of the victims who provided evidence but say there could well be others who have not been identified.