China’s ministry of state security detained Sandy Phan-Gillis in March and she is being investigated on accusations of “spying and stealing state secrets”, according to the website savesandy.org, which provides information on the woman and her case.

This undated photo provided to media by Jeff Gillis shows his wife, Sandy Phan-Gillis, who has-been arrested (taken in to custody) in China on charges of spying and stealing state secrets. According to the Houston Chronicle, soon after Sandy was detained, she told the party she was travelling with that they should go ahead because she is attending to some personal matter.

Ministry spokesman Hong Lei said the woman was healthy and was able to meet with American officials.

She was initially held under house arrested but was transferred to a detention centre over the weekend and is now being held in the southwestern city of Nanning, they said.

“I can’t think of any reason why the Chinese government would have done this”, he said. The Houston Chronicle reported Monday that she was in a trade delegation to China when she was stopped on her way to Macau.

He added that “it was unusual , but she’s been there [China] hundreds of times”, so he thought little of it.

While USA consular officials have met the USA citizen, her family and friends have not been given access to her, they say.

Australian national Stern Hu, an executive with the mining giant Rio Tinto, was sentenced to 10 years in prison in 2010 on bribery and trade secrets charges.

A Canadian couple in the Chinese border town of Dandong, who helped Christians escaping North Korea, were accused of spying past year .

The U.S. Embassy in Beijing referred questions to the U.S. State Department’s consular affairs office, which did not immediately respond to a request for comment.

“Sandy is in very poor health”, the statement said, adding that she suffers from high blood pressure, high cholesterol and high blood sugar.

China announced that the wife was released on bail in February, though her husband had been placed under formal criminal detention.