There should be an end to prosecutions for Troubles-related killings, Northern Ireland's attorney general has said. John Larkin said there should be no further police investigations, inquests or inquiries into any relevant killings that took place before the signing of the Good Friday Agreement in 1998. That means all deaths caused by paramilitaries, police or the Army. Mr Larkin said his proposal was not a formal amnesty, but was a logical consequence of the Agreement.

More than 3,500 people were killed during three decades of conflict in Northern Ireland.

The comments come as former US diplomat Richard Haass tries to broker a political agreement over how to deal with the legacy of Northern Ireland's past, as well as controversial parades and the flying of flags.

"More than 15 years have passed since the Belfast Agreement, there have been very few prosecutions, and every competent criminal lawyer will tell you the prospects of conviction diminish, perhaps exponentially, with each passing year, so we are in a position now where I think we have to take stock," Mr Larkin told the BBC.

"It strikes me that the time has come to think about putting a line, set at Good Friday 1998, with respect to prosecutions, inquests and other inquiries."

'Crimes still crimes'

In addition to the end to all criminal prosecutions and coroners' inquests, if adopted his proposals would result in the abolition of the Historical Enquiries Team, the body set up to review killings during the period known as the Troubles.

The attorney general, who is the chief legal adviser to the Stormont Executive for civil and criminal matters, said the proposal was a logical consequence of the terms of the Good Friday Agreement.

He said the agreement included the 1997 arms decommissioning statute, which meant any weapons handed over to be put beyond use could not be tested forensically to obtain evidence in criminal prosecutions.

Legislation introduced in 1999 covering the recovery of the Disappeared - people murdered and secretly buried by republican paramilitaries - states that information that leads to remains being found can be examined only to establish identity, not forensically.

That means they cannot be used as evidence for a criminal trial.

Another part of the agreement, the Sentences Act, provided for vastly reduced jail terms for anyone convicted of a Troubles-related killing - anyone convicted would spend a maximum of two years in prison.

Mr Larkin said his proposal did not constitute an amnesty, although many will interpret it as one.

"Sometimes the fact of an amnesty can be that that which was a crime ceases to be a crime. That wouldn't be the position here, it would simply be that no criminal proceedings would be possible with respect to those offences," he said.

"So there is an evenness. At present we have very good tools, subject to the point I've made about the passage of time, for critiquing the state, but we don't have them for bringing to account those who have committed offences against the state."

Help relatives

In the absence of legal proceedings, Mr Larkin believes relatives of Troubles victims should be given as much access as possible to records to help them find out what happened to their loved ones.

"We can't really be surprised if people don't tell us as long as the theoretical threat of prosecution remains," he said.

So what about relatives of victims who say they want the killers to be brought before the courts?

Mr Larkin said there was little realistic possibility of successful prosecutions taking place.

"I have had conversations with people in that very position, I've drawn attention to the logic of the existing legislation and I have also drawn attention to the extreme improbability of criminal proceedings ever taking place," he said.

"What I have found in those circumstances is a huge hurt, but also a huge comprehension of the broader dimensions of this problem."

Mr Larkin, who has made a submission to the talks process chaired by Dr Haass, said he believed he had a duty to stimulate debate on how society deals with the legacy of the past.

"Of course, the question of whether the law changes is not for me, that's for the politicians," he said.