A lawyer for one of the 20 defendants indicted in an international arms smuggling ring argued in federal court yesterday that his client deserves a separate, pre-trial hearing to strike a confession the lawyer says was forced by Armenian authorities who tortured his client.

George Goltzer said that after the Armenian police tortured Armen Barseghyan, they told him to confess to the American officials or face further abuse. Armenian police then sat in the same room with FBI officials as they questioned Mr. Barseghyan, Mr. Goltzer said.

“The Armenian agents repeatedly beat him with, among other things, rubber pipes” and “administered electric shock,” Mr. Goltzer wrote in the motion. As Mr. Barseghyan “was questioned by Americans, an Armenian agent was in the room staring at him.”

Mr. Goltzer said that by allowing the Armenian officials who tortured Mr. Barseghyan to be in the same room as the American officials, the Americans did not sufficiently separate themselves from the Armenian police. As a result, Mr. Goltzer said, the Armenians’ torture of Mr. Barseghyan can be linked to the Americans, thus allowing the confession to be thrown out in an American court.

In earlier cases, the Supreme Court has ruled that a confession can only be deemed coerced and stricken if an American official was the abusive party; independent coercion by another country’s official is not enough.

Mr. Barseghyan was extradited from Armenia in April 2005, a month after the FBI simultaneously arrested the other defendants in New York, Los Angeles, and Fort Lauderdale, Fla.

The defendants are alleged to have imported surface-to-air missiles, grenade launchers, anti-tank missiles, mortar launchers, and machine guns from Russia, Georgia, and Ukraine.The FBI used wiretaps and a confidential informer who posed as an arms buyer with links to Al Qaeda to compile hundreds of hours of conversation among the defendants, who were indicted in March 2005.