A Chinese J-11 military fighter jet flies above the Taiwan Strait near Pingtan, the closest land of mainland China to the island of Taiwan, in southeastern China's Fujian Province on Aug. 5, 2022 (AP Photo/Ng Han Guan, File)

German Defense Minister Boris Pistorius on Saturday said he told China's National Defense Minister Li Shangfu that he expects Beijing to cease hiring former Luftwaffe pilots to train their own air force.

The reason, although not mentioned in the minister's comments, is owed to the fact that some of these pilots might disclose to Chinese authorities classified information and confidential operational tactics, as per a report by Der Spiegel detailed on Friday.

"I raised the question of Germany air force pilots who have apparently been recruited to train (Chinese) pilots," Defence Minister Boris Pistorius told reporters about his meeting with Li on the margins of a defense and security conference in Singapore on Saturday.

"I indicated clearly that I expected this practice to cease immediately and told him he probably wouldn't be very pleased either if I tried to do the same thing," Pistorius added.

Li "didn't deny it but downplayed its importance", he continued, as per a ministry readout of his comments to the press.

According to the Der Spiegel report, some of the pilots are also former NATO pilots who were employed by China to train Chinese army pilots.

They are reportedly receiving wages via shell companies located in Seychelles, sources said.

The matter has been of particular relevance for the parliamentary committee overseeing the German secret services.

"We are worried that military personnel who have previously worked for the German state could be in jobs that could lead them to betray state secrets," the head of the parliamentary committee told ZDF.

Some of the pilots who were hired by China flew Eurofighter fighter jets and took part in NATO drills.

"China is attempting, via external agencies, to recruit former NATO pilots ... former German Bundeswehr pilots ... A significant danger that not just basic flight proficiency will be imparted, but that relevant tactics, techniques, and procedures will be manifested," the German ministry said yesterday, as quoted by Der Spiegel.

The ministry is planning to launch an inquiry into the matter, ZDF reports, noting that similar occurences happened in the UK and the US in recent years.

The Chinese Air Force recruited several retired German military pilots through the Lode-Tech shell company of Chinese national businessman Su Bin.

In 2016, Su Bin was sentenced to four years in jail in the US for stealing "cutting-edge" US military secrets.

In 2017, he was deported to China in exchange for a Canadian couple that was suspected of espionage by Chinese authorities.

Der Spiegel said that the former German pilots that were hired by China's Air Force are allegedly taking part in military drills at the Qiqihar military airfield near the Russian border.