Details of an alleged criminal conspiracy by MI5 to obstruct one of the most sensitive murder inquiries of the 30 years of conflict in Northern Ireland have been exposed following the emergence of key sections of a previously secret police report on the affair.



The report details how officers of the security service were said to have concealed the existence of an audio recording of an incident in which RUC officers shot dead an unarmed teenage boy, Michael Tighe, and then destroyed the tape to prevent it falling into the hands of the detective who was investigating the killing.

Compiled at the height of a tumultuous 1980s political scandal known as the Stalker affair, the report recommended that two officers – thought to be the highest-ranking MI5 officers in the province – be prosecuted for perverting the course of justice.

Its author, Colin Sampson, then chief constable of West Yorkshire, condemned MI5’s concealment of a key piece of evidence during a murder inquiry as “wholly reprehensible”, and said the officers responsible were guilty of “nothing less than a grave abuse of their unique position”. He added in his report that the excuse they had given for failing to surrender the recording was “patently dishonest”.

Sampson reported that he had gathered sufficient evidence to justify the prosecution of three MI5 officers for their roles in the conspiracy. However, he recommended that the most junior officer, who had carried out the act of destruction, be granted immunity in return for giving evidence against the two high-ranking MI5 officers.

He also recommended that three senior police officers be prosecuted for conspiring to pervert the course of justice.

In the event, none were prosecuted after the then attorney general, Sir Patrick Mayhew, said the government did not believe it to be in the interests of national security to bring them to trial. Mayhew’s statement made no mention of MI5, however, and was couched in a way that led MPs to believe that Sampson had recommended only police officers be prosecuted.

Sampson’s report remained secret for 30 years. However, sections of the report were included in submissions to the court of appeal in Belfast when a survivor of the police shooting, Martin McCauley, successfully appealed against his conviction for possession of rifles.

The Criminal Cases Review Commission, the official body that examines alleged miscarriages of justice, had referred McCauley’s case to the appeal court. The commission is thought to have interviewed people who had listened to the surveillance recording to establish whether any warnings could be heard being shouted before Tighe was shot dead.

After McCauley’s conviction was quashed, the director of public prosecutions of Northern Ireland requested a new investigation into the concealment and destruction of the surveillance recording.

The police ombudsman of Northern Ireland is currently investigating the actions of a group of former Special Branch officers, while detectives from Police Scotland are investigating the conduct of a number of former MI5 officers.