This was 1980, and if Margaret Thatcher knew about the activities of military intelligence agents such as Fulton, then she was also aware her own military officers were planning to infiltrate British soldiers as "moles" into the IRA. These moles were ordered by their handlers to carry out terrorist crimes in order to keep their cover within the Provos so they could feed information on other leading republicans back to security forces.

For almost two years the Sunday Herald has been investigating the activities of the FRU - the Force Research Unit, an ultra-secret wing of British military intelligence. Fulton worked for the FRU for much of his career as an IRA mole. This unit, which has been under investigation by Scotland Yard commissioner Sir John Stevens for more than a decade, was involved in the murder of civilians in Northern Ireland.

Nicholas Benwell, a detective sergeant formerly attached to the Stevens Inquiry, says the Scotland Yard team came to one conclusion: that military intelligence was colluding with terrorists to help them kill so-called "legitimate targets" such as active republicans. FRU handlers passed documents and photographs to their agents operating within paramilitary groups detailing targets' movements and the whereabouts of their homes. Pictures were also handed over to help gunmen identify their victims. But there was a problem. The targeting was far from professional and many of the victims of these government-backed hit squads were innocent civilians.