A BBC television programme broadcast tonight will allege that the RUC Chief Constable, Sir Ronnie Flanagan, told a UN rapporteur that some lawyers in Northern Ireland were "working for the paramilitaries".
Sir Ronnie has denied the claim, and a statement issued by the RUC press office last night expressed his irritation, saying the Chief Constable has repeatedly "made it clear" that he had not made the comments attributed to him.
Panorama will examine allegations of collusion between the British army, the RUC and loyalist terror groups.
In the programme, entitled Careless Talk, Dr Param Cumaraswamy claims that during a meeting at the RUC headquarters in Belfast in October 1997, Sir Ronnie said he had "more than a suspicion" about lawyers "working for a military agenda", and that there were "reams of documented evidence" to prove it.
On seeing a draft of Dr Curaraswamy's report, the programme alleges the Chief Constable phoned Dr Cumaraswamy's office asking him to delete the remarks from the final version of his report. In an interview with Panorama, Sir Ronnie says he has "no recollection" of any phone conversation with Dr Cumaraswamy regarding the withdrawal of his remarks from the report. He also categorically denies making the original comments.
In April, Dr Cumaraswamy won a case at the International Court of Justice in The Hague, which means he cannot be sued for libel over any comments he makes in his position as a UN rapporteur. Last year he clashed with Sir Louis Blom-Cooper, the commissioner for holding centres, when their recollections of a meeting differed.
Sir Ronnie's alleged remarks are particularly contentious in view of the fact that the loyalist paramilitaries charged with the killing 10 years ago of the Belfast lawyer, Mr Pat Finucane, have claimed he was an IRA member.
Panorama features an interview with Mr Brian Gillen, one of Mr Finucane's former clients, who alleges he was told by police that the lawyer would be killed. In the programme, the Chief Constable insists he did not know until last spring about allegations by the human rights group, British Irish Watch, that RUC officers incited the UFF to shoot Mr Finucane. However, Panorama claims to have a letter from Sir Ronnie acknowledging receipt of the group's report six months earlier.
The Deputy Commissioner of the Metropolitan Police in London, Mr John Stevens, has been charged with reopening the inquiry into Mr Finucane's death. The first two drafts of Mr Stevens's report have never been made public, despite repeated requests by the UN.
The programme also looks into allegations of threats made against the Lurgan solicitor, Mrs Rosemary Nelson, who was killed by loyalist paramilitaries in March. Mrs Nelson repeatedly claimed she had been threatened by RUC officers following her work defending a leading republican, Mr Colin Duffy. The programme's allegations come at a sensitive time for the force as Mr Chris Patten, the former Hong Kong governor, is due to complete his report on the future of the RUC by September.