The son of murdered solicitor Pat Finucane has said his family are considering requesting direct intervention from the White House to the British government, in relation to unresolved matters surrounding the murder of his father in February 1989.
Speaking on RTÉ's Today with Claire Byrne programme, Michael Finucane said his family have previously received support from President-elect Joe Biden, when he was a serving senator.
"We've also had support in the past from one Senator Joe Biden, who is the President-elect of the United States.
"He clearly has a very strong link to Ireland, and I would imagine we would probably be seeking support from the White House, perhaps even direct intervention with the British Prime Minister, to try and resolve this case," Mr Finucane said.
He said it is "unsustainable" for the UK government to defend its decision not to order a public inquiry into the murder on the basis that the police ombudsman and the PSNI are currently conducting investigations on the case.
Mr Finucane said his family were "not surprised" by the decision of the British government against holding a public inquiry.
"What was very strange was the reasons that he gave us, namely that the PSNI were still conducting an investigation as was the police ombudsman.
"I think that decision has moved from the realm of strange, to the realm of unsustainable, given the announcements by the Chief Constable of the PSNI and also the police ombudsman that neither of them are pursuing any current investigations into my father's case," he added.
"It's really becoming right quite frustrating that the British government are coming up with reasons that other state agencies are openly and publicly disagreeing with.
"And, one can only conclude that there is just a stubborn refusal to hold an inquiry, for reasons, best known to themselves," he said.
Mr Finucane said he does not expect any honour to be shown by the British government, but he said he expects it to abide by the rule of law.
He said: "What I do expect is that they will abide by the judgment of the UK Supreme Court. That's their Supreme Court.
"And if they have any respect for the rule of law in their own country at all, then they should honour that judgment and implement the public inquiry that will provide the effective investigation that the UK Supreme Court said was lacking."
He said his family will consider initiating a fresh case to challenge the decision that's been taken.
"The Taoiseach and the Minister for Foreign Affairs have been extraordinarily helpful.
"I imagine we'd be talking to them and they will in turn be discussing the matter with the Secretary of State and the Prime Minister."
Meanwhile, Northern Ireland's most senior police officer has again said there are no viable lines of inquiry in the investigation.
PSNI Chief Constable Simon Byrne said the case was a reminder of the difficulties of policing the past.
On Monday, Northern Secretary Brandon Lewis cited an upcoming police review of the case as one of his reasons for not establishing a public inquiry.
Several examinations of the case have concluded that there was collusion between the loyalist killers and members of the British security forces.
Speaking to the Northern Ireland Policing Board this afternoon, the Chief Constable said previous investigations and reports into the murder "satisfy us that there remain no viable lines of inquiry".
Mr Byrne confirmed that police will begin a review process next week, but stressed that "this is a very complex case".
