WASHINGTON — A US man once employed as a guard at a US consulate in China has been charged with attempting to pass defense information to the government in Beijing, the US Justice Department said Wednesday.

The new charge came in a superseding indictment for Bryan Underwood, 31, atop previous charges of making false statements to US officials.

According to the Justice Department statement, from about March to August, Underwood "knowingly and unlawfully attempted to communicate photographs and other information relating to the national defense to representatives of the People's Republic of China (PRC)."

The statement did not specify the city in which Underwood had worked.

Underwood made the attempts "with the intent and reason to believe that these materials would be used to the injury of the United States and to the advantage of a foreign nation," US officials said.

The superseding indictment returned by a federal grand jury in Washington on Wednesday comes after initial charges were made against him on August 31.

Underwood had been scheduled to appear at a status hearing earlier this month, and when he failed to present himself in court, FBI agents located him in Los Angeles and arrested him on September 24.

He now also faces charges of failing to appear in court in accordance with the terms of his release.

If convicted, Underwood faces a maximum potential sentence of life in prison.

"Our national security depends upon our ability to keep our most sensitive information confidential," US attorney Ronald Machen said in a statement, adding his lying to US officials to allegedly cover up his actions was a "betrayal" of US interests.