China’s military is recruiting former British Air Force pilots for training skills and experience, and the British government is working to end the practice, the British Ministry of Defense said on Tuesday, as cited by CNBC and news.ro.

“We are taking action to stop Chinese recruitment schemes aimed at poaching former British Armed Forces pilots to train People’s Liberation Army personnel in the People’s Republic of China,” a ministry official told CNBC.

About 30 former British military pilots went to work in China to train personnel in the People’s Liberation Army

Around 30 former British military pilots have gone to work in China to train personnel in the People’s Liberation Army, according to a BBC article on the subject published on Tuesday.

Recruitment is said to be on the rise as ex-pilots are offered high salaries to work for the Chinese.

“All current and former personnel are already covered by the State Secrets Act and we are reviewing the use of confidentiality and non-disclosure agreements within defence, while the new National Security Bill will create additional tools to address today’s security challenges, including – the ministry spokesman added.

While the training and recruitment of pilots is not illegal under UK law, the practice poses an intelligence risk as British officials suspect the Chinese military is keen to learn about the tactics and operations used by Western pilots. This knowledge would be useful in the event of a conflict over Taiwan, for example.

China’s Ministry of Defense did not comment

“The Chinese can use ‘instructors’ not only to train new pilots, which is also a threat, but also as intelligence tools to determine the strengths and weaknesses of the West,” said Dave De Roche, a professor and senior military member at the US National Defense University.

Ex-pilots are also being offered large sums of money, with the BBC quoting a Western official as saying the salary was as high as $270,000 a year.

A former Australian Air Force pilot, speaking on condition of anonymity because of professional restrictions, told CNBC that he was offered nearly $1 million a year to work for the Chinese military.

Tensions between China and the West have risen sharply in recent years

Jeremy Fleming, head of Britain’s GCHQ intelligence service, said last week that Chinese technology posed a serious threat to Britain’s security and prosperity.

And President Joe Biden, as part of the US national security strategy, called China “the most important geopolitical challenge for America.”

According to the national security strategy, China is “the only competitor with both the intent to change the international order and, increasingly, the economic, diplomatic, military, and technological power to advance that goal.”