Finucane: More questions for undercover unit

Pat Finucane was murdered in his Belfast home

It is two years since the start of the Stevens inquiry into the murder of Belfast solicitor Pat Finucane and the wider allegations of collusion between security forces and the loyalist paramilitaries who shot him.

In this special report for BBC News Online, our chief security correspondent in Belfast Brian Rowan, examines the prospects of the police ever bringing the killers to justice.

The team of English detectives investigating the UDA/UFF murder of Pat Finucane, and the claims of collusion, will question members of a secret army intelligence-gathering unit within the next few weeks.

It is understood four soldiers are to be interviewed, some of whom have been questioned before.

Brian Rowan: Work on Stevens report has begun

They were part of the British Army's Force Research Unit, which is at the centre of allegations of security force collusion with loyalist gunmen.

One of FRU's agents, Brian Nelson, who operated inside the UDA/UFF, was jailed in 1992 on charges including five counts of conspiracy to murder. He has been linked to the targeting of the Belfast solicitor.

Although now released, Nelson has been interviewed as part of the latest investigation and it is unlikely he will face new charges.

One source told BBC News Online there would be "huge problems re-prosecuting him".

Nor is it likely that the gunmen involved in the 1989 murder will be brought before the courts.

Pat Finucane: Prosecution for murder unlikely

A source close to the investigation said the chances of getting the "trigger puller" were "between zero and 5%.

"It's the gap between intelligence and evidence," he told me.

That intelligence information has provided detectives with a clear picture of the loyalist "planners, conspirators and executors" involved in the Finucane murder plot - some of whom still hold senior positions in the UDA/UFF structure in the Shankill area of Belfast.

But bringing them to justice may prove impossible.

The investigation into the Finucane shooting is headed by the now Commissioner of the Metropolitan Police, Sir John Stevens.

Sir John Stevens heads inquiry

He is expected to report his findings to the RUC Chief Constable Sir Ronnie Flanagan before the end of this year. Work on the report has already begun.

In the way this investigation works, "constitutionally" the report will be "owned by the RUC chief constable" and it will be Sir Ronnie who decides what happens with it.

Many will demand publication once the document is delivered but, given the nature of some of the matters under investigation, there will be issues that will not reach the public domain.

Sources are predicting that the report, when completed, will "paint the best picture ever" of how the intelligence gathering system worked at the time of the Finucane murder, where it was "vulnerable" and the lessons to be learned.

Serious questions

Before then, the four FRU soldiers will be interviewed including the officer in charge of the unit at the time of Pat Finucane's murder, two captains - one known as 'Z' -and one of Brian Nelson's handlers identified as "Mags".

The fact that some are being re-interviewed suggests that detectives believe there are soldiers who still have serious questions to answer.

It is also known that another of Nelson's handlers - now a police officer - was suspended by the RUC after being arrested and interviewed by the Stevens team.

Sources say he was questioned about "his historic role" in FRU and then released. There are suggestions the officer may seek a judicial review of his suspension.

William Stobie: Accused of supplying guns

The Stevens team have charged a former RUC special branch agent, William Stobie, in connection with the murder of Pat Finucane.

Stobie was a UDA/UFF "quartermaster" who has admitted supplying the murder weapons but he claims he tipped off special branch that a shooting was imminent and that no action was taken.

The case is now with the courts but there continues to be speculation that it could collapse. The main witness against Stobie has now refused to give evidence.

The probing of the Finucane murder has brought the roles of Stobie and Brian Nelson to the surface and the perception of security force collusion has been hardened by the detail of their involvement.

Report delivery

Another suspected security force agent may also have had knowledge of the killing. Loyalists believe that Tommy Lyttle, who was so-called UDA brigadier in the Shankill area at the time of the murder, was working for the police.

He died six years ago and what he knew, or did not know, can never be explored.

As the Finucane investigation continues, many other avenues will be explored and the report of the Stevens team could be delivered within six months.

It is at that point that the UK government will have to decide on its response to continuing calls for a public inquiry into the murder.

That is one of the key demands nationalist politicians say must be met ahead of any acceptance of new policing arrangements in Northern Ireland and it is an issue that will be high up the agenda in the new political negotiations about to begin.