The United States Supreme Court on Monday refused to hear an appeal by four former Guantanamo inmates who want to sue the US government for torture they say they endured during their stay at the prison camp, a move the inmates' lawyers say could pave the way for future torture practices by the US military.

The four plaintiffs -- Rhuhel Ahmed, Jamal al-Harith, Asif Iqbal and Shafiq Rasul -- say they were subjected to numerous forms of physical abuse and religious humiliation, including having their beards shaved, being threatened with dogs and being placed in cells that were alternately very hot or very cold. The lawsuit also alleges that one of the guards at Guantanamo flushed a Koran down the toilet to anger and humiliate the prisoners. One of the inmates, Ahmed, has also alleged "sexual abuse."

Three of the detainees -- Ahmed, Iqbal and Rasul -- are British residents who say they were in Afghanistan in 2001 to provide humanitarian relief in the wake of the US invasion when they were kidnapped by Afghan warlord Rashid Dostum, a US ally, and accused of belonging to Al Qaeda.

The fourth inmate, Al-Harith, says he was in Pakistan on a religious retreat when he was kidnapped by the Taliban and taken to a prison in Afghanistan. When the Taliban fled and US forces seized the prison, Al-Harith was taken into US custody. All four were transferred to Guantanamo by the US military and spent more than two years there before being returned to the UK.

With the help of the Center for Constitutional Rights, the four men have been fighting to sue former Defense Secretary Donald Rumsfeld and 10 other military officials since 2004. After a federal appeals court in Washington, DC, rejected their lawsuit in 2008, the Supreme Court ordered the lower court to reconsider its ruling, in light of another Supreme Court ruling, earlier that year, that Guantanamo inmates had constitutional protection.

When the case returned to the lower court, the Obama administration argued against the plaintiffs, saying that former Guantanamo detainees don't have any constitutional rights. And even if they did, the administration argued, the defendants should be immune from prosecution because the Supreme Court hadn't yet ruled that detainees have rights at the time the alleged abuses took place.

The lower court accepted this argument and quashed the lawsuit yet again. On Monday, the Supreme Court effectively upheld that ruling by refusing to hear the appeal.

"It is an awful day for the rule of law and common decency when the Supreme Court lets stand such an inhuman decision," said Eric Lewis, the lead attorney for the plaintiffs, in a statement from the CCR. "The final word on whether these men had a right not to be tortured or a right to practice their religion free from abuse is that they did not. Future prospective torturers can now draw comfort from this decision."

"Where can these men seek justice now for the terrible things that were done to them?" asked CCR attorney Shayana Kadidal. "The entire world recognizes that torture and religious humiliation are never permissible tools for a government, yet our highest court seems to think otherwise."