The US Supreme Court on Monday put CACI International Inc a step closer to facing a trial in a lawsuit by three Iraqi former detainees who have accused employees of the defence contractor of directing their torture at the Abu Ghraib prison near Baghdad.

The justices declined to hear CACI’s appeal of a lower court’s 2019 decision that favored the three Iraqi men, whose suit against the Virginia-based company was filed in 2008 under a 1789 US law called the Alien Tort Statute that can be used to pursue legal claims over alleged human rights abuses.

The Richmond, Virginia-based 4th US Circuit Court of Appeals in 2019 refused to let the company immediately appeal a federal judge’s earlier ruling that said CACI was immune from being sued because it was working as a government contractor.

The company has argued that it should be protected under a different and more muscular legal doctrine known as derivative sovereign immunity that can be invoked to shield government contractors from liability under certain circumstances...