The Mintz Group's closed office in Beijing on March 24, 2023.
Hong Kong CNN  — 

Chinese authorities have closed the Beijing office of Mintz Group, an American corporate due diligence firm, and detained five local staff, the company said Friday.

In a statement provided to CNN, Mintz Group, which is based in New York, said it had not received any official legal notice regarding a case against the company and had requested that authorities release its employees.

“Our top priority is the safety and well being of our colleagues in China, where we have retained legal counsel to engage with the authorities and support our people and their families,” it said.

The move comes as ties between the world’s two biggest economies are at their worst in decades following months of rising diplomatic tension, including the downing of a suspected Chinese spy balloon over North America.

It also follows unusually direct comments by Chinese leader Xi Jinping targeting the United States, accusing Washington of trying to “contain” and “suppress” China.

Chinese Foreign Ministry spokesperson Mao Ning was asked about the employees’ detention at a regular press briefing in Beijing on Friday, but said she was not aware of the situation.

Mintz said it was ready to work with the Chinese authorities to “resolve any misunderstanding that may have led to these events.”

The Mintz Group, which says it has more than 450 staff in 18 cities around the world, offers a range of services, including due diligence checks, asset tracing, fraud investigations, corruption investigations and background checks for corporate clients.

In its statement, it said it was licensed to conduct legitimate business in China and has “always operated transparently, ethically and in compliance with applicable laws and regulations.”

It is not the first time a Western due diligence company has been targeted by Chinese authorities.

In 2013, Shanghai authorities arrested Peter Humphrey, a former British journalist turned corporate investigator, and his American wife and business partner Yu Yingzeng, who operated consultancy company, ChinaWhys.

Both were convicted of illegally obtaining private information. Humphrey was sentenced to two-and-a-half years in prison, while Yu received a two-year sentence.