WASHINGTON (Reuters) - The Army said on Tuesday it was looking into whether U.S. forces in Iraq put prisoners in a cage with lions in 2003, but Defense Secretary Donald Rumsfeld called the accusation by two Iraqi men "far-fetched." Two Iraqi businessmen, Sherzad Khalid and Thahe Sabbar, made the allegation as part of a lawsuit against Rumsfeld and top U.S. military commanders in Iraq filed by two rights groups, the American Civil Liberties union" and Human Rights First. The men contend U.S. jailers took them to a cage containing lions on the grounds of a presidential palace in Baghdad during an interrogation seeking some sort of a confession, forced them into the cage entrance then pulled them back and shut the cage door when the lions approached. Army spokesman Paul Boyce said officials were trying to determine whether such an incident took place, but added that the Army had not launched a formal criminal investigation. "We are just somewhat perplexed that some 800 days after this incident allegedly occurred and these individuals were detained that this is the first time there's been any reference to a lion," Boyce said. Asked about the lion allegations, Rumsfeld told a Pentagon briefing, "It seems quite far-fetched. Obviously everything that everyone alleges is looked into." The United States faced international condemnation last year after photographs emerged showing American forces physically abusing and sexually humiliating Iraqi prisoners at Abu Ghraib jail. The U.S. military has acknowledged numerous instances in which American forces abused detainees in Iraq and Afghanistan, but has said no policy allowed for such treatment. NEVER CHARGED Asked about the lion allegation, Rumsfeld said terrorists were trained to lie about how they were treated while imprisoned. Asked by a reporter whether he was saying the lion incident never happened, Rumsfeld responded, "I didn't say that. You heard precisely what I said. I spoke very precisely. And you can get a transcript of it if you really want to know what I said." Pentagon spokesman Bryan Whitman said that as far as he knew U.S. personnel had never used lions with detainees. Some of the Abu Ghraib abuse involved U.S. forces terrifying Iraqi prisoners with snarling military working dogs. A Pentagon policy directive this month specifically prohibited using dogs in such a manner. Khalid was held for two months by U.S. forces; Sabbar was held for six months. Both say they did nothing to warrant their detention and stated they faced routine severe beatings and sexual abuse while imprisoned by U.S. forces. They were never charged with a crime. Boyce said the Army, on the subject of detainee abuse, had conducted 400 criminal investigations, 73 courts-martial, prepared 60,000 pages worth of documents and participated in 12 investigations with the Department of Defense and senior regional commanders. "Nowhere in any of these previous 2-1/2 years worth of investigations and documents has there been any reference to lions being used in detainee operations," Boyce said.