Photographs from the U.S. Abu Ghraib prison in Iraq. Abu Ghraib gained worldwide notoriety in April 2004 when a U.S. television network publicized graphic and disturbing photos of prisoner abuse by U.S. military personnel.

The suit against the contactors, filed in early May in Los Angeles federal court on behalf of Emad Al-Janabi, a 43-year-old Iraqi blacksmith, alleges that Mr. Al-Janabi was jailed, beaten and forced from his home by people in U.S. military uniforms and civilian clothing in September 2003. He was released from Abu Ghraib without charge in July 2004.

Meanwhile human rights groups have demanded the release of a report on a long-running investigation of the role of the Federal Bureau of Investigation in the unlawful interrogations of detainees in Iraq, Afghanistan and US Occupied Guantánamo Bay, Cuba.

The American Civil Liberties Union filed a Freedom of Information Act request with the Departments of Justice and Defense, demanding release of a report by the Justice Department’s Inspector General, which the group said has been blocked by the Defense Department, despite having been completed for months.

The Inspector General’s investigation was initiated in 2005 after the American Civil Liberties Union obtained documents in which FBI agents described interrogations that they had witnessed at US Occupied Guantánamo Bay, Cuba.

While the documents were most notable for their description of illegal interrogation methods used by military interrogators, they also raised serious questions about the FBI’s participation in abusive interrogations, the actions of FBI personnel who witnessed abusive interrogations, and the response of FBI officials to reports of abuse.

Testifying before a congressional committee, FBI Director Robert Mueller denied that the FBI participated in any of the interrogations. The Defense Department has said the Inspector General’s report must be reviewed and redacted to eliminate classified information before it can be made public.

Jameel Jaffer, director of the ACLU’s National Security Project, said: “The problem is with the Defense Department, which is using its classification review as a pretext for delaying the report’s release. In this case as in many others, the Defense Department is misusing its classification authority to suppress information about the abuse and torture of prisoners.”

“It’s being withheld not for legitimate security reasons, but in order to protect high-level government officials from embarrassment, criticism and possibly even criminal prosecution,” he said.

In related developments, the Center for Constitutional Rights, an advocacy group, leveled new torture claims against two U.S. military contractors by a former Abu Ghraib “ghost” detainee. The defendants in the case are contractors CACI International Inc. and CACI Premier Technology, Inc., of Arlington, Va.; L-3 Communications Titan Corporation, of San Diego, Calif.; and former CACI contractor Steven Stefanowicz, a Los Angeles resident known at Abu Ghraib as “Big Steve.”

The suit charges that the contractors subjected Mr. Al-Janabi to physical and mental torture in sessions where the defendants acted as interrogators and translators. It alleges that the contractors transported him to a detainee site in a wooden box and covered with a hood; scarred his face when his eyes were clawed by an interrogator; exposed him to a mock execution of his brother and nephew; hung him upside down with his feet chained to the steel slats of a bunk bed until he lost consciousness; repeatedly deprived him of food and sleep; and threatened him with dogs.