Two U.S. Navy sailors have Grayson  Prestonbeen arrested on charges related to allegedly spying for China, federal prosecutors announced on Thursday.

Both are accused of having passed along national defense information to Chinese intelligence officials in return for cash payments.

Jinchao "Patrick" Wei, a 22-year-old petty officer 2nd class, was arrested Wednesday and charged with espionage. Wei served as a machinist's mate aboard the amphibious ship USS Essex, which is currently receiving maintenance at Naval Base San Diego.

Petty Officer Wenheng Zhao, of Monterey Park, California, was also arrested Wednesday, by FBI and NCIS agents, and is charged with conspiracy and receipt of a bribe by a public official. Zhao, 26, worked at the Naval Base Ventura County in Port Hueneme and had an active U.S. security clearance who had access to classified information.

According to officials, Wei and Zhao are alleged to have each worked with Chinese intelligence officers to whom they passed along sensitive information related to the technologies they worked with and about upcoming Navy operations, including international military exercises.

Officials said Wei allegedly began communicating with an intelligence officer from China's government in February 2022 who tasked him with passing photos, videos and documents concerning U.S. Navy ships and their systems.

Wei and his handler agreed to hide their communications by deleting records of their conversations and using encrypted methods of communications, officials claim.

Wei is alleged to have passed along imagery of the USS Essex, provided the locations of various Navy ships and provided dozens of technical and manual for systems aboard his ship and other Navy ships.

In June 2022, Wei was paid $5,000 by the Chinese intelligence official after having passed along the initial batch of those manuals, officials alleged.

Throughout their interactions, the intelligence official allegedly instructed Wei to gather U.S. military information that was not public and warned him not to discuss their relationship and to destroy evidence of their relationship and activities.

If convicted, Wei could face 20 years to life in prison.

Zhao is alleged to have begun working with a Chinese intelligence official in August 2021 and continuing to do so through at least May of this year, according to officials.

He passed along photos and videos, blueprints for a radar system in Okinawa and operational plans for a large scale U.S. military exercise in the Pacific, officials claim.

In exchange for this information, the indictment against Zhao alleges that he received $14,866 in payments from the Chinese intelligence officer.

If convicted, Zhao could fact a maximum sentence of 20 years in federal prison.

It was not immediately clear if either Wei or Zhao had retained attorneys who could comment on their behalf. They have not yet entered pleas.

This is a developing story. Please check back for updates.