The Court of Appeal has reserved its decision in the case of a man who wants to sue the authorities in Saudi Arabia for £2m over torture allegations.
Ronald Jones, 50, of Crawley, West Sussex, is one of four who claim they were taken into custody after a bomb in Riyadh in 2001 and brutally tortured.
The High Court struck out the claim in July 2003, ruling the authorities were protected by "sovereign immunity".
The Saudi government has denied the claims of all four men.
The court heard on Tuesday that the tax adviser, who injured in the bomb which went off outside a book store, was detained for 67 days.
His counsel, Mr Michael Crystal QC, said Mr Jones was repeatedly beaten on his hands and feet, slapped in the face, suspended by his arms for prolonged periods and subjected to sleep deprivation and mind-altering drugs.
Mr Jones, originally from Lanarkshire, Scotland, had been diagnosed with severe post traumatic stress disorder, Mr Crystal said.
The damages claim is against the Saudi Ministry of the Interior and the investigator who Mr Jones says tortured him.
The outcome of the case will affect claims also being brought by three other former detainees - Sandy Mitchell from Glasgow, Les Walker from the Wirral and British-Canadian Bill Sampson from Penrith.
All four claim they were tortured into confessing to a 2000 bombing campaign which killed Briton Christopher Rodway and an American.
On Tuesday, Mr Crystal said the High Court's decision violated Mr Jones' right of access to the English courts, enshrined in Article Six of the European Convention of Human Rights.
He said Saudi Arabia's claim of state immunity was against "accepted principles of international law" and breached the UN Convention Against Torture.
Mr Crystal said an international "prohibition on torture" took priority over other aspects of treaty and international law.
At the end of a two-day hearing, the Master of the Rolls, Lord Phillips, sitting with Lord Justice Mance and Lord Justice Neuberger, did not give a date for announcing their ruling.