The four men, Shafiq Rasul, Asif Iqbal, Rhuhel Ahmed and Jamal Al-Harith, all British citizens and residents, were sent back to Britain from Guantanamo Bay in 2004.
They allege that during their time in the US prison facility in Guantanamo Bay in Cuba they were beaten, shackled in painful positions, threatened by dogs and subjected to extreme medical care.
They also say they were harassed while practicing their religion, including the forced shaving of their beards, banning or interrupting their prayers, denying them copies of the Qu'ran and prayer mats and throwing a copy of the Qu'ran into a toilet bucket.
The lawsuit argues that their treatment violated the US Religious Freedom Restoration Act, which says the US government "shall not substantially burden a person's exercise of religion".
A three-judge panel of the US circuit court of appeals had unanimously ruled against them in January because they said the men were considered "aliens and were located outside sovereign United States territory" at the time of the alleged abuse.
Rasul, Iqbal and Ahmed have denied any links to al-Qaeda and the Taliban, saying they had travelled to Afghanistan from Pakistan to provide humanitarian relief the month after the September 11, 2001 attacks in the US, AP reported.
Al-Harith says he traveled to Pakistan the same month to attend a religious retreat, AP said.