By James Vicini
WASHINGTON (Reuters) - The U.S. Supreme Court questioned on Wednesday whether former Attorney General John Ashcroft can be held liable for the detention of an American Muslim after the September 11 attacks in 2001.
The justices appeared divided during arguments in the case of Abdullah al-Kidd, who sued Ashcroft for what he says was his wrongful arrest, mistreatment and detention for 16 days in 2003 under a U.S. "material witness" law.
Kidd was arrested by the FBI in 2003 at nearby Dulles International Airport before departing for Saudi Arabia for language and religious study.
He was held as a material witness in the Idaho case of Sami al-Hussayen, who had been charged with visa fraud and making false statements. Kidd had helped at an Islamic charity in Idaho with al-Hussayen. He was never asked to testify in the case.
The Obama administration defended Ashcroft, who served under Republican George W. Bush, and who helped craft the tough anti-terrorism legal policies adopted after the September 11 attacks.
Acting Solicitor General Neal Katyal said Ashcroft has immunity from the lawsuit seeking personal money damages. Allowing the case to go forward would interfere with the ability of government prosecutors to do their job, he said.
At issue is a law that allows material witnesses -- those who might have key information and be crucial to a case -- to be held even though they are not suspected of wrongdoing and not charged with a crime.
Liberal Justice Ruth Bader Ginsburg asked Katyal about the allegations of abuse by Kidd, who was born in Kansas and who attended the University of Idaho in the mid-1990s, when he converted to Islam.
"There are allegations here that this man was kept awake, the lights shining in his cell for 24 hours, kept without clothes," Ginsburg said. "Is there a remedy that he has for that obvious mistreatment?"
Justice Sonia Sotomayor also questioned Katyal.
She said that under the administration's argument "prosecutors can out of spite, out of pure investigative reasoning, out of whatever motive they have, just lock people up."
Civil liberties groups have said Kidd was one of about 70 men, almost all Muslims, arrested and held in the months and years after the September 11 attacks under the law that compels witnesses to testify before grand juries and at trials.
Supreme Court conservatives, Chief Justice John Roberts and Justice Samuel Alito, seemed to back Ashcroft.
Roberts mentioned the "particularly heavy" burden in allowing such lawsuits to go forward.
Lee Gelernt of the American Civil Liberties Union, representing Kidd, said the law can only be used to secure testimony, not to detain and investigate a witness.
Alito seemed concerned by Gelernt's argument that witnesses cannot be detained if they say they will show up for trial, despite evidence of a risk of fleeing the country.
A ruling in the case is expected before July.
The Supreme Court case is John Ashcroft v. Abdullah al-Kidd, No. 10-98.
(Editing by Jackie Frank)