Berlin — German authorities have detained a U.S. citizen on suspicion of attempting to pass sensitive information about American military operations in Germany to Chinese intelligence agencies. The suspect has been identified only as Martin D., under German privacy laws. He is a 37-year-old former civilian contractor employed by the U.S. military who was arrested by the German Federal Criminal Police Office (BKA) Thursday morning in Frankfurt, according to the Federal Prosecutor’s Office.

The case is being investigated by the federal prosecutor’s office, which ordered the arrest on a warrant issued on Oct. 30 by a federal judge.

“Due to a pressing suspicion, the accused stands charged with offering himself as an agent to a foreign intelligence service,” the prosecutor’s office said in a statement Thursday. 

Martin D. is accused of contacting Chinese government authorities earlier this year, offering to share confidential information he acquired during his work with the U.S. military in Germany. His former employment involved working as a civilian contractor for a private firm that provided services to American forces based in the central state of Hessen, where Frankfurt is located.

Investigators believe Martin D. initiated contact with Chinese intelligence operatives, proposing to hand over classified information about the U.S. military presence and operations within Germany. The prosecutor’s statement said he was “urgently suspected of having expressed a willingness to conduct intelligence activities for a foreign intelligence service.”

In response to a potential national security threat, German counter-intelligence launched an investigation, with the BKA leading the operation. Martin D.’s residence was searched as part of the operation but authorities have not said what, if any, materials were seized.

The investigation was launched based on initial information gathered by Germany’s domestic intelligence agency, the Office for the Protection of the Constitution (BfV), which has been increasing vigilance against foreign intelligence activities within the country.

The arrest comes amid growing concern in Western capitals about espionage and sabotage activities by foreign powers, particularly China and Russia. Just days ago, a source familiar with the matter that American and European law enforcement agencies were jointly investigating whether incendiary devices that detonated in July at DHL logistics hubs in Germany and the U.K. were part of a larger operation directed by Russia’s military intelligence agency.

Martin D. was scheduled to be brought before a judge at the German Federal Court of Justice Thursday. The judge was to formally present the arrest warrant and decide whether the accused can be held in pre-trial detention. 

Several people have been arrested in Germany this year and accused of spying for China. In April, federal prosecutors detained three Germans in Düsseldorf and Bad Homburg who have been accused of passing military technology information. Another high-profile case involved the arrest of a former assistant to far-right AfD party politician Maximilian Krah, who’s accused of sharing EU Parliament data and surveilling Chinese dissidents in Germany.

In early October, a Chinese woman working for a logistics company at Leipzig/Halle Airport was also detained on suspicion of espionage. She is accused of providing the former Krah associate with information about flights, cargo and passengers, particularly regarding military goods and individuals linked to a German defense firm.

If convicted, Martin D. could face serious charges under German laws on espionage and unauthorized intelligence activities that carry lengthy prison sentences.