 A breakthrough came in 2005 after senior officers from West Yorkshire Police's Homicide and Major Enquiry Team (HMET), headed by Det Chief Supt Chris Gregg, decided to review the case.A small piece of the gummed seal from one of the envelopes was located in a forensic laboratory in London and, following publicity about the cold case review, while the original hoax tape was retrieved from a retired scientist who had worked on the original investigation.As a result of this cold case review, DNA from envelopes sent by Humble as part of the hoax were matched in the United Kingdom National DNA Database with samples police had obtained from Humble in an unrelated incident in 2001, when he had been arrested and cautioned for being drunk and disorderly.