A Korean American Christian working on aid projects along China's border with North Korea has apparently been detained by Chinese authorities on suspicion of embezzlement.

Peter Hahn, a naturalised US citizen, was taken in for questioning by authorities in Tumen on Tuesday and subjected to six hours of interrogation, the Sydney Morning Herald reports.

The 73-year-old was then placed under detention, although his lawyer Zhang Peihong says he has not yet been formally charged.

Mr Hahn has spent the last two decades running NGOs  in the area and supporters believe the allegations against him are politically motivated.

It's not the first run in with the Chinese authorities Mr Hahn has experienced this year.  In July, authorities reportedly raided his office and confiscated his passport and other documents, as well as his computer and car.

Mr Hahn's wife, Eunice, believes the action by the authorities reflects a hostility towards foreign NGOs.

"I feel that the Chinese government doesn't want foreign NGOs working on North Korea any more," she said, according to Fairfax Media.

"In the past, it just left us alone; but now it is cracking down." 

Mr Zhang said the claims against his client were "groundless" and "impossible to stand up".