The US Supreme Court has refused to hear a case lodged by two Guantanamo Bay prisoners who sought to challenge the legality of US military courts.
The US Supreme Court decided it would not hear the detainees' case
The court gave no reason for its decision but three out of nine judges said they would have heard the case.
A total of four votes would have been sufficient to have the case heard by the Supreme Court.
The case was brought by Salim Ahmed Hamdan, from Yemen, and Omar Khadr, a Canadian citizen.
Ahmed Hamdan won a landmark case last year when the US Supreme Court ruled the military tribunal system illegal.
The decision forced US President George W Bush to return to Congress to obtain the legal authority to continue with the system of military tribunals.
Lawyers for the pair of Guantanamo detainees claim that the new system is identical to the old one which the Supreme Court rejected a year ago.
The high court sided with Mr Bush's administration, which insisted that the trials should take place before the two men could bring an appeal.
Ahmed Hamdan is accused of being Osama bin Laden's personal bodyguard and driver and Omar Khadr, 20, faces a charge of murder for throwing a grenade that killed a US soldier.
The two men are among the first detainees that the US government plans to intends to prosecute this summer in its military courts.
Both men had urged the court to hear their case before they go to trial and asked the Supreme Court to clarify whether they were protected by the constitution.
Some 385 detainees are held at Guantanamo Bay, in Cuba.