Alleged Al Qaeda operative Jose Padilla claims he was tortured during his 3 1/2 years in U.S. custody as an enemy combatant, including threats of execution and being forced stand for long periods.

Padilla's lawyers are asking a federal judge to dismiss the terror support charges against him because he suffered from "outrageous government conduct" during more than 1,300 days in military custody.

"Many of the conditions Mr. Padilla experienced were inhumane and caused him great physical and psychological pain," Padilla attorney Michael Caruso said in court papers. "The pain and anguish visited upon Mr. Padilla will continue to haunt him for the remainder of his life."

Click here for FOXNews.com's War on Terror Center.

Click here for FOXNews.com's Homeland Security Center.

U.S. Attorney R. Alexander Acosta in Miami declined comment. Prosecutors and Defense Department officials intend to respond to the allegations by Nov. 13.

Padilla, a 36-year-old former Chicago gang member, was declared an enemy combatant by President Bush in June 2002, shortly after he was arrested when he arrived at Chicago's O'Hare International Airport. U.S. authorities initially claimed he was on an Al Qaeda mission to detonate a radioactive "dirty bomb" in a U.S. city.

He was held and interrogated at a Navy brig, where he was usually held in a small isolation cell, until he was transferred to civilian custody in January to face federal terrorism support charges in Miami along with two others. Trial on those charges, which do not mention the "dirty bomb" allegations, is scheduled to begin Jan. 22.

In the court papers, filed last month, Padilla claims that:

—Interrogators threatened him with "imminent execution" or with painful cuts.

—He was often forced to wear a hood and stand in "stress positions" for long periods. Similar tactics were used by U.S. personnel at Iraq's notorious Abu Ghraib prison.

—He was given a form of a "truth serum" drug that may have been LSD or PCP.

—Noxious fumes were sometimes introduced into his cell and he was forced to endure extreme heat and cold, bright lights or total darkness, denied opportunities to shower for weeks and deprived of sleep.

—He was not provided with a copy of the Koran, the Muslim holy book, for almost two years.

It is the first time that Padilla has made these detailed allegations about his treatment. His lawyers cited no corroborating evidence or witnesses.

The Bush administration has repeatedly said it does not torture prisoners despite aggressive interrogation tactics, especially in the war on terrorism, that have drawn broad criticism from international human rights groups.

Caruso acknowledged in the documents that such dismissal requests are rarely granted.

The judge has not indicated when she will rule.