When ruthless drug baron John Haase was sentenced to 18 years' imprisonment for heroin-trafficking in 1995, it was a major victory for Customs and the police. But in a shock move, after Haase and his partner Paul Bennett had served only 11 months, then Home Secretary Michael Howard signed a Royal Pardon for their release.

Howard defended his decision by revealing that Haase and Bennett had become invaluable informants. But Haase had in fact duped the authorities, and far from being forced into hiding as a supergrass, he gained new kudos among the criminal underworld for beating the system so audaciously.

Graham Johnson interviewed Haase at Whitemoor prison and has obtained a copy of his sworn affidavit revealing the truth behind the Royal Pardon scandal. Allegations of huge bribes, mass fabrication of evidence and dark powers at the heart of the justice system make this an explosive expose of Britain's number-one drug kingpin.