The former head of Germany's foreign intelligence service, August Hanning, who is being held on suspicion of espionage, had long-standing contacts with a former high-ranking Chinese general, the magazine "Spiegel" reported, quoted by Reuters.
According to the publication, Hanning, who left the German intelligence service in 2005, had traveled to China several times, where he knew a former official who worked at the Chinese embassy in the former communist East Germany (GDR).
The magazine said that the former major general, identified as Wang Jiangzheng, is a recognized expert on German affairs and has translated a number of German books into Chinese.
Hanning was detained this week on suspicion of shared information from confidential documents provided to him by his former chief of staff with foreign intelligence agents.
The alleged actions took place after his retirement, when he worked as an independent security consultant.
The prosecutor's office did not comment on exactly what materials it believes were provided, nor to whom they were passed on.
Hanning's lawyer told "Spiegel" that his client is being unfairly persecuted.