Met chief finally penetrates dark world of army agents

Senior diplomat and up to 20 intelligence personnel could face criminal charges

The position presently held by Brigadier Gordon Kerr as military attaché in Beijing is a highly sensitive one, yet his alleged association with one of Northern Ireland's most controversial sectarian killings could result in his prosecution in a British court.

Brigadier Kerr's three-year stint at the murky nexus between military intelligence and loyalist assassination squads has led to the preparation of a report which will now be passed to the Director of Public Prosecutions.

But the difficulties of penetrating the secrets of the intelligence world are evident in the fact that the Metropolitan Police Commissioner, Sir John Stevens, has been involved in three investigations over the course of more than a decade. Even now, he indicated yesterday, new documents and material are still being unearthed. Documentation from both the Ministry of Defence and MI5 are said to have been obtained by his detectives in recent months.

It is common ground that the Army and indeed other agencies had agents within the loyalist groups that killed scores of people in the mid-1980s. The key point is whether the military effort was aimed at saving lives or whether intelligence personnel tried to direct loyalist gunmen towards active republicans, and troublesome figures such as the solicitor Pat Finucane.

From 1986 to 1989 Brigadier Kerr commanded a top-secret intelligence unit styled the Force Research Unit. Despite its innocuous name, it ran agents within loyalist groups, most notably the Belfast man Brian Nelson, inserted by the FRU within the Ulster Defence Association.

At one point Nelson took the UDA's copious but disorganised documents on republican suspects to the FRU, who weeded out and streamlined the files and returned them to him. In a subsequent statement to detectives, Brigadier Kerr said his unit "reasoned that we could persuade the UDA to centralise their targeting through Nelson and to concentrate their targeting on known IRA activists". He insisted, however, that IRA activists were "far harder targets" than innocent Catholics, and that the strategy had been aimed at saving lives.

As a result of an early Stevens investigation, Nelson pleaded guilty to a series of charges. In an unusual move Brigadier Kerr, a soft-spoken Scot, appeared in court to give evidence on his behalf, referred to as Colonel J. He said Nelson had warned of attacks such as a loyalist plan to place a limpet mine under a car used by the Sinn Fein president, Gerry Adams. He described Nelson as a very courageous man "who was bound to make mistakes and undoubtedly he did".

Stressing that the saving of life was paramount, the brigadier said that Nelson had produced information that led to more than 700 reports concerning threats to more than 200 individuals.

This assertion has been challenged by detectives who worked on the Stevens investigations. One former detective said: "I was incredulous. It just wasn't right, it wasn't correct. I could only find maybe two cases where the information given by Nelson may have been helpful in preventing attacks."

Brigadier Kerr has always denied allegations of conspiracy to murder.