Former Sinn Féin president Gerry Adams has said he is disappointed but not surprised to have failed in his legal bid to overturn two historic convictions.
Mr Adams had challenged the legality of two convictions from 1975, which related to escape bids while he was held at the Maze Prison without trial.
His lawyers argued that the order used to intern him was not legal, so he therefore should not have been prosecuted for trying to escape from what they asserted was unlawful custody.
The interim custody order to hold Mr Adams had not been considered by the then Secretary of State, and was instead signed by a junior minister at the Northern Ireland Office.
The lawyers held that the 1972 Detention of Terrorists Order required senior level authorisation.
However, three Court of Appeal judges rejected that argument on Wednesday.
The judgement stated: “The Court of Appeal was satisfied that the ICO (Interim Custody Order) was valid having been made by the Minister on behalf of the Secretary of State.
“The Court was accordingly satisfied that the appellant’s convictions are safe and dismissed the appeal.”
Mr Adams was first detained in March 1972, but was released in June that year to take part in secret talks in London.
He was rearrested in July 1973 at a Belfast house and held at the Maze Prison, also known as Long Kesh internment camp.
Mr Adams had challenged subsequent convictions handed down by two separate Diplock court trials - cases tried by a single judge sitting without a jury - relating to two attempts to escape from internment.
Reacting to the judgment, he said: “I am disappointed, though not entirely surprised, by today’s High Court decision.
“I will now discuss with my legal advisers what options, including an appeal, are open to me.”