The US Supreme Court agreed on Monday to decide whether former Attorney General John Ashcroft can be held personally responsible for the detention and interrogation of an American Muslim who was wrongly suspected of involvement with terrorists.

Abdullah Al-Kidd, a former football star at the University of Idaho who converted to Islam, was arrested and handcuffed by FBI agents at Dulles International Airport as he was about to fly to Saudi Arabia in 2003. He was held in a high-security jail cell and interrogated.

The warrant that authorized his arrest said nothing of criminal wrongdoing. Federal agents did not possess the probable cause necessary to justify his arrest as a criminal suspect. Instead, they relied on a federal statute that authorizes the temporary detention of a witness to ensure the witness will be available to testify at a trial.

Mr. Kidd was never called to testify at a trial. He was never charged with a crime.

Kidd’s lawyers say federal officials were using the so-called material witness statute as a pretext to imprison and interrogate individuals the authorities suspected might have information about terrorists. They say the alleged policy had two purposes. It was a form of preventative detention, a way to disrupt imagined terror plots without having to demonstrate to a neutral judge proof of an actual terror plot. It also permitted authorities to hold certain suspects –including US citizens like Kidd – in harsh, prisonlike conditions to facilitate coercive interrogations without Miranda warnings or access to a lawyer.

After his release, Kidd filed a lawsuit against Attorney General Ashcroft and other federal officials claiming they violated his constitutional right to be free from unreasonable searches and seizures and his right to a fair judicial process before being imprisoned and punished.

Some of those government officials have agreed to pay a settlement to Kidd rather than go forward with a jury trial. Ashcroft is fighting the lawsuit, arguing that the attorney general has immunity from such legal action.

Government lawyers defending Ashcroft say that even if Kidd’s constitutional rights were violated, those rights were not clearly established at the time Kidd was taken into custody. If they weren’t clearly established, Ashcroft is protected by qualified immunity.

A federal judge refused to dismiss Kidd’s lawsuit, and a panel of the Ninth US Circuit Court of Appeals voted 2-to-1 to allow the suit against Ashcroft to move forward.

In urging the Supreme Court to take up Ashcroft’s appeal and dismiss the lawsuit, Acting Solicitor General Neal Katyal argued that a former attorney general should not be subject to “burdensome litigation and potential damages for the conduct of his subordinates.”

Mr. Katyal said the Ninth Circuit’s decision poses long-term harmful consequences for the country. The decision, if allowed to stand, would “threaten the ability of prosecutors to discharge their duties without fear of personal liability, severely limit the usefulness of the material witness statute, and substantially chill officers in the exercise of important government functions.”

He said government officials did not act improperly in their use of the material witness statute as a means to investigate a potential witness.

Kidd’s lawyer, Lee Gelernt of the American Civil Liberties Union, said Ashcroft and others engaged in “gross abuse” of the material witness statute.

He said Ashcroft approved a Justice Department strategy to aggressively use the material witness statute for preventative detentions rather than merely to ensure the availability of a witness at trial. Ashcroft revealed the strategy during an October 2001 press briefing.

“Today, I am announcing several steps that we are taking to enhance our ability to protect the United States from the threat of terrorist aliens,” Ashcroft said. “These measures form one part of the department’s concentrated strategy to prevent terrorist attacks by taking suspected terrorists off the streets,” he said. “Aggressive detention of lawbreakers and material witnesses is vital to preventing, disrupting, or delaying new attacks.”

In his brief to the court, Mr. Gelernt urged the justices not to take up the case. He said the Ninth Circuit’s ruling was correct and that there was no disagreement among the other circuit courts.

The Supreme Court in recent years has handed down a series of decisions making it more difficult for individuals caught up in post-9/11 counterterrorism operations to seek redress in the courts. The justices have made pleading standards tougher, requiring plaintiffs to produce more evidence to survive an initial motion to dismiss a case. And the justices have broadly interpreted immunity for government officials involved in similar cases.

Kidd was held in prisonlike conditions for 16 days. After that, he was subject to government supervision for 15 months. He was ordered to live with his wife and in-laws, surrender his passport, limit his travel to a four-state region, and regularly report to a probation officer.

The ordeal took a toll. Kidd’s marriage broke up. He was also fired from his job working for a contractor at an Air Force base after being turned down for a security clearance because of his earlier detention.

The case, Ashcroft v. Al-Kidd, will be set for argument later in the term.