The US Supreme Court has ruled that terror suspects held at Guantanamo Bay in Cuba can use the US legal system to challenge their detention.
Many Guantanamo detainees have been held for more than two years
The six-to-three ruling is seen as a major blow to the Bush administration and could herald hundreds of appeals in US courts on behalf of the inmates.
Lower US courts had previously ruled that Guantanamo prisoners were beyond US legal jurisdiction.
The ruling did not pass judgement on the guilt or innocence of any detainee.
Of the 600-odd terror suspects held at Guantanamo Bay most were rounded up in Afghanistan and Pakistan during the US-led operation against al-Qaeda and the Taleban.
No blank cheque
The Supreme Court did not address the issues of human rights surrounding the men's capture and detention without trial.
Human rights groups have challenged the legal basis for their continued incarceration.
The detainees comprise nationals from more than 40 countries.
Many were captured in 2001, during the early months of the US operation in Afghanistan.
About 150 have been transferred from Guantanamo - many of them to be detained by their own governments.
Two Britons who were freed from Guantanamo Bay in March and released without charge in the UK, Shasiq Rasul and Asif Iqbal, urged the US government to inform all detainees of their right to take their case to US courts and to provide them with lawyers "to make that access a reality".
In a separate but related ruling, the Supreme Court decided that US citizens designated as "enemy combatants" could be detained without trial - but that those held also had the right to challenge their detention in US courts.
In that case - which centres on US-born detainee Yaser Esam Hamdi - Justice Sandra Day O'Connor said that a state of war was "not a blank cheque for the president when it comes to the rights of the nation's
US President George W Bush has announced controversial plans to try the Guantanamo detainees in military tribunals, rather than civilian courts.