A Belfast court will hear allegations this week that a senior member of the British royal family abused a young boy at a notorious children's home in the city in the 1970s.

Arthur Smyth, a one time resident of Kincora, has waived his anonymity to make allegations against Lord Louis Mountbatten, an uncle of King Charles III.

Lord Mountbatten was murdered along with three other people when the IRA detonated a bomb on his boat in Mullaghmore, Co Sligo, in 1979.

Mr Smyth’s solicitor, Kevin Winters, said the allegations would form part of a civil action against state bodies responsible for the care of children in Kincora.

A public inquiry in 2017 found that 39 boys had been abused over the years at Kincora children's home

"He alleges to have been abused twice as an 11-year-old by the deceased royal," Mr Winters said.

"It’s the first time that someone has stepped forward to take allegations against Lord Mountbatten into a court.

"That decision hasn’t been taken lightly. He understands only too well that it will be a deeply unpopular case with many people coming as it does within weeks of the passing of the queen.

"However, litigation involving mental, physical and sex abuse isn’t undertaken to deliberately offend sensitivities. It’s taken for many reasons including exposing perpetrators and the institutions or other agencies which helped suppress the truth.

Mr Smyth now lives in Australia. He told the Sunday Life Newspaper he had been abused by Lord Mountbatten in 1977 but only realised who he was two years later from news reports after his murder.

The police are also part of the legal action because of their failure to adequately investigate allegations about the children’s home which were first raised in the early seventies.

A public inquiry into historical abuse at a series of institutions reported in 2017.

It found that 39 boys had been abused over the years at Kincora, and children there had been let down by the state.

Three former Kincora staff were jailed in 1981 for abusing 11 boys. They have since died.

The public inquiry found no evidence to substantiate claims that security force agencies had been complicit in the abuse.

A report by Northern Ireland’s Police Ombudsman last month found major deficiencies in how the then RUC had responded to abuse complaints raised by residents at the time and said officers had failed in their duty to the victims.

The PSNI, which replaced the RUC, apologised.