The positions taken by the Police Ombudsman of Northern Ireland Dr Michael Maguire and a senior British police chief constable about the background to the arrests of two Belfast journalists "are incompatible", Sinn Féin has said.
Journalists Trevor Birney and Barry McCaffrey were interviewed by police in August on allegations that documents used in a documentary about the 1994 Loughinisland massacre had been stolen from the Ombudsman.
However, the Ombudsman has now three times denied ever making a complaint of theft to the police, while Durham Constabulary has twice insisted that the Ombudsman did do so.
Lawyers for the two men have already said they will seek to have the investigation stopped, since it would have no legal basis if a complaint of theft was never made.
"The positions of the police and the Ombudsman's Office are incompatible, there is a clear contradiction and the public need to know which one is correct," said Sinn Féin's Northern Ireland policing spokesman Gerry Kelly.
“Whatever the truth of that issue is, the police were wrong to arrest two reputable journalists whose documentary exposed the truth of what happened at Loughinisland,” he said.
The documentary No Stone Unturned looked into the police investigation into the massacre of six men by loyalist paramilitaries in a pub in Loughinisland, Co Down, in 1994. It alleged there had been collusion between the RUC and the yet-to-be apprehended Loughinisland killers.
Meanwhile, the SDLP's Dolores Kelly noted the strong rejection of Durham's claims by the Ombudsman. She said: "The ombudsman is very clear in what he is saying. He hasn't resiled from that. I have very great respect for Michael Maguire. I have confidence in him. I trust him as the figurehead from the office.
“Who exactly was the source of the complaint to Durham and how was that verified by the receiver of the complaint? They are questions I would want answered,” she said.
Accepting that a "serious conflict" exists, the UUP's Alan Chambers, a former RUC reserve officer, said: "We are all second guessing here.
“I don’t know where the truth lies. It would be unhelpful to speculate. We, everybody, deserves for this situation to be clarified urgently.
“It could be as simple as a breakdown in communications but it is a pretty serious matter for that. You would like to think these things are well documented at both ends,” he said.
The Alliance Party's deputy leader Stephen Farry said his party had already raised its concerns about the Police Service of Northern Ireland's decision to arrest the two journalists.
“There are potentially far reaching implications. The contradictory positions from Durham police and the Ombudsman raise further detailed questions. All of these need to be clarified urgently.”
The chairman of the National Union of Journalist's Belfast and District Branch chairman Gerry Carson said "the twists and turns" are "rapidly approaching" farce.
The arrests, said Mr Carson, were an attempt "to warn other journalists not to criticise the police - a practice adopted in countries where democracy and the freedom of the press is demonised".
The NUJ is hosting a free screening of the documentary at Cineworld in Dublin on Monday at 6.30pm. McCaffrey and Birney will answer questions.