By Edith Honan

NEW YORK, Dec 11 (Reuters) - The mother of a U.S. citizen who was detained as an "enemy combatant" from 2002 to 2006 and says he was tortured, filed a petition against the United States government on Tuesday with the Inter-American Commission on Human Rights.

Jose Padilla - a former Chicago gang member and a Muslim convert who became an al Qaeda recruit and was convicted on terrorism charges - has maintained his designation as an enemy combatant, his military detention and his treatment in custody were unconstitutional.

However, Padilla's lawsuit against former Defense Secretary Donald Rumsfeld and other officials accountable was dismissed, and in June the U.S. Supreme Court rejected his appeal.

The American Civil Liberties Union, which filed the petition on behalf of Padilla's mother, Estela Lebron, said her son's treatment violated the American Declaration of the Rights and Duties of Man.

The organization is calling on the United States to "publicly acknowledge the violations and apologize for its unlawful conduct."

"The U.S. has historically been a leader in ensuring access to justice for human rights violations around the world, but it has effectively closed the courtroom door to all victims and survivors of the Bush administration's torture regime," said Steven Watt, senior staff attorney with the ACLU Human Rights Program.

"Denied redress in U.S. courts, torture survivors like Padilla are now left with no choice but to turn to international justice."

The IACHR is an independent human rights body of the Organization of American States, a Washington-based group founded to foster cooperation in the Americas. The ACLU filed the petition jointly with the Yale Law School's Lowenstein International Human Rights Clinic.

The U.S. Justice Department had no immediate comment.

"LAST CHANCE"

Padilla was taken into custody in Chicago in May 2002 after arriving at O'Hare International Airport from Pakistan via Switzerland.

U.S. Attorney General John Ashcroft said at the time Padilla was suspected of plotting to detonate a radioactive "dirty bomb" in a U.S. city, but Padilla never was charged with planning such an attack.

President George W. Bush declared Padilla an enemy combatant a month later, saying he possessed valuable intelligence about al Qaeda.

Padilla was taken to a Navy jail in South Carolina, where he said he was held in isolation, shackled for hours in excruciating positions and subjected to prolonged periods of constant light and then complete darkness.

He was convicted in 2007 in a U.S. court in Miami on charges of conspiracy to murder, kidnap and maim people abroad, conspiracy to provide material support for terrorism and providing material support for terrorism.

Padilla is being held in a federal prison in Colorado.

"No human being deserves what happened to our family, and I will continue to work for my son and for justice as long as I'm breathing," said Lebron in a statement. "As a mother, I want to be sure this never happens to anyone else. This petition may be my last chance."

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