By Jon Silverman
Legal affairs analyst
The law lords have ruled that secret evidence which might have been obtained by torture cannot be used against terror suspects in UK courts - what are the implications?
The law lords disagreed over standard of proof
Like the Pinochet judgment of 1999 which held that former heads of state did not have immunity from torture charges, this law lords ruling, too, will have international reverberations.
It is a trenchant affirmation of the supremacy of the common law over the procedural rules of the Special Immigration Appeals Commission.
As the senior law lord, Lord Bingham, said: "Torture and its fruits" have been regarded with abhorrence for over five centuries in English law.
But in July 2002, SIAC decided that it was entitled to consider evidence which may have been obtained under torture. That decision is now null and void.
The effect of the law lords' judgment may be felt in countries which also have a common law system, such as Canada and Australia.
And even the United States will take note of it.
Carla Ferstman, Director of Redress, one of the 14 human rights organisations which were a party to the case, said: " This must have an impact on the process known as extraordinary rendition.
"There is already an inquiry by the government of Canada into the seizure and rendition of a Syrian-Canadian citizen to Syria where he was tortured.
"I hope that the law lords' declaration will put even more pressure on the US and other countries to stop the practice."
Standard of proof
Although the judgment on the substantive issue was unanimous, the law lords disagreed about a significant matter - standard of proof.
Three took the view that if, after an inquiry, SIAC could not reach a decision on whether evidence had been obtained under torture, it should exclude it.
But the majority held that SIAC was entitled to admit such evidence if it was left in doubt about how it had been gathered.
Given that chunks of SIAC hearings are held in secret, even the lawyers for appellants may not know why the commission has decided to admit some evidence, despite claims that it has been tainted by the use of torture.
The law lords addressed the important ethical dilemma of whether the police or security forces should act on information which was the product of torture.
Lord Nicholls summed up their view that "it would be ludicrous for them to disregard information about a ticking bomb if it had been procured by torture."
But this was not the same as using that information in legal proceedings.
SIAC will now have to review all the cases on which it has reached a decision, where torture may have been a factor in the gathering of evidence.
Whether the government will be deflected from its policy of trying to reach memoranda of understanding with states where torture is practised remains to be seen.