Alleged state collusion and cover-up of a paedophile ring at a notorious Belfast care home amounts to a systemic failure, the Court of Appeal has heard.
Counsel for one abuse victim argued that the scale of the Kincora scandal, which includes claims of British security service involvement, warrants an investigation that will "vindicate" his human rights.
Gary Hoy (54), is seeking to overturn a verdict that the probe into the home should remain within the remit of a Stormont-commissioned body.
He believes the ongoing Historical Institutional Abuse (HIA) Inquiry sitting in Banbridge lacks the power to properly scrutinise what went on at the home in east Belfast.
Mr Hoy's legal team insist he is entitled to an investigation that complies with Article 3 of the European Convention on Human Rights, dealing with freedom from torture, inhuman and degrading treatment or punishment.
The legal action is a bid to force a full independent inquiry with the power to compel witnesses and the security services to hand over documents.
Proceedings were issued after the Government refused to include Kincora within a separate Westminster investigation established by Home Secretary Theresa May and headed by New Zealand judge Lowell Goddard.
Mrs May has said the HIA tribunal being overseen by Sir Anthony Hart is the best forum for examining the allegations.
With MI5 accused of covering up the sexual abuse throughout the 1970s to protect an intelligence-gathering operation, lawyers for Mr Hoy contend that the current arrangements cannot compel the security services to hand over documents or testify.
It has long been suspected that well-known figures within the British establishment, including high-ranking civil servants and senior military officers, were involved.
Last month the High Court dismissed his bid to judicially review the decision to bring the Kincora claims within the remit of the HIA.
A judge said the legal action was "premature and misconceived". But with the HIA set to begin examining Kincora, an urgent appeal is being brought against that verdict.
Mr Hoy's barrister argued yesterday that any inquiry should vindicate his human rights.
Ashley Underwood QC contended: "There's abuse here of a nature which involves Article 3 breaches."
At one point Lord Chief Justice Sir Declan Morgan questioned if he was looking at an issue of systemic failure.
The barrister replied: "Yes."