"We hope that the German side will... stop using so-called espionage cases to engage in manipulation and smearing, and earnestly safeguard the legitimate rights and interests of Chinese citizens in Germany," foreign ministry spokesman Lin Jian said.

German media reported that a Chinese man was detained by security guards before he was arrested by police after taking photographs at the Kiel-Wik naval base on December 9.

The northern port is home to German naval installations and shipyards of the defence giant Thyssenkrupp, which builds submarines there.

Beijing on Friday said it was "not aware" of the specific case.

But Lin said China "has always required its citizens overseas to comply with local laws and regulations".

Germany in early October said it had arrested a Chinese woman accused of spying on the country's defence industry while working in a logistics company, including at Leipzig airport in eastern Germany.

Named only as Yaqi X., she allegedly reported to another suspected Beijing agent now under arrest, Jian G., who was working in the office of a German far-right member of the European Parliament, Maximilian Krah.

News magazine Der Spiegel, citing unnamed security sources, said that 38-year-old Yaqi X. had especially targeted the arms giant Rheinmetall, which is involved in making Leopard tanks and uses Leipzig airport for cargo flights.

ehl-oho/sco

THYSSENKRUPP

RHEINMETALL