A group of former detainees at the infamous Abu Ghraib prison in Iraq will not be able to sue military contractors who they say participated in torture and other illegal acts of abuse at the US-run detention facility in 2003 and 2004.

The US Supreme Court on Monday declined without comment to take up the case of Saleh v. Titan Corporation.

The suit raised the issue of whether private contractors hired by the US military to perform services in a war zone may be held accountable for allegedly participating in acts of torture and other war crimes.

A federal appeals court in Washington threw out the suit against two contractors, Titan Corporation, which provided Arabic translation services, and CACI International, which provided interrogators. On Monday, the detainees lost their bid to reinstate the lawsuit.

Images of detainees at Abu Ghraib enduring harsh and abusive interrogation tactics sparked international outrage. The tactics included forced nudity, sexual humiliation, beatings, hooding, stress positions, isolation, and sleep deprivation. In one case, family members were allegedly forced to watch US interrogators suspend a man by his arms and beat him so severely that he later died. Some detainees were allegedly raped.

A handful of relatively low-level military personnel at the prison were prosecuted for some of the abuses.

The class-action lawsuit on behalf of 250 former Iraqi detainees sought compensatory and punitive damages for the victims of the alleged abuses. The lawsuit was aimed at widening the sphere of responsibility for the abuses by examining the role of private contractor interrogators and translators who allegedly participated in illegal conduct at the prison.

In dismissing the case, a three-judge appeals court panel ruled 2-1 that claims against the contractors were precluded under a doctrine the two majority judges called “battlefield preemption.”

Writing for the court, Judge Laurence Silberman said: “During wartime, where a private service contractor is integrated into combatant activities over which the military retains command authority, a tort claim [for damages] arising out of the contractor’s engagement in such activities shall be preempted.”

The government acted quickly to prosecute the offending military personnel, but no similar proceedings were initiated against military contractors at the prison, Silberman wrote. “This fact alone indicates the government’s perception of the contract employees’ role in the Abu Ghraib scandal,” the judge said.

The appeals court also ruled that the former Iraqi detainees were not empowered under the Alien Tort Statute to file a lawsuit in a US court seeking to enforce a violation of the law of nations. The judges said that although torture committed by a government is a violation of a settled international norms, the same act by a private contractor is not.

“Congress has never created this cause of action,” Silberman wrote. While Congress has empowered US residents to sue foreign governments for torture, federal law makers excluded from the law the possibility of filing a similar suit against American military officials overseas, or private individuals working with the US government overseas.

In a dissent, Appeals Court Judge Merrick Garland said he would allow the Iraqi detainees’ lawsuit to move forward against both military contractors.

“No act of Congress and no judicial precedent bars the plaintiffs from suing the private contractors – who were neither soldiers nor civilian government employees,” Garland wrote.

“Neither President Obama nor President Bush nor any other executive branch officials has suggested that subjecting the contractors to tort liability for the conduct at issue here would interfere with the nation’s foreign policy or the executive’s ability to wage war,” he said. “To the contrary, the Department of Defense has repeatedly stated that employees of private contractors accompanying the Armed Forces in the field are NOT within the military’s chain of command, and that such contractors ARE subject to civil liability.”

In a brief urging the high court to take up the case, the detainees’ lawyers said it arises at a time when contractors outnumber members of the military in overseas operations. “This is a case about the commission of war crimes by private actors who violated state, federal, and international law,” said Vincent Parrett in his brief to the court.

“There are 217,832 contractor personnel providing services to the United States in Iraq and Afghanistan, answering not to the military chain of command but to for-profit corporations who receive a total of over $5 billion annually for their services,” Parrett wrote. “The [appeals court’s] holding has eviscerated one of the most effective means of deterring them from violating the law.”