BEIJING (AP) — Chinese authorities are investigating an American businesswoman on suspicion that she threatened China's national security, the Foreign Ministry said Tuesday, confirming earlier media reports that Phan Phan-Gillis of Houston was detained earlier this year while traveling in the country.

Ministry spokesman Hong Lei said the woman was healthy and was able to meet with American officials. He said Beijing is handling the case according to China's laws.

The U.S. State Department said Phan-Gillis is being held by the Chinese Ministry of State Security in the southern city of Nanning and that she was visited six times by American consular officers since her March 20 arrest. The department said in a statement Tuesday it was closely monitoring the case.

Phan-Gillis is a Vietnamese-American of Chinese descent. The Houston Chronicle reported Monday that she was in a trade delegation to China when she was stopped on her way to Macau.

Her husband, Jeff Gillis, told the Chronicle that he was publicizing her six-month detention as Chinese President Xi Jinping visits the United States this week in hopes of pressuring Beijing and Washington to secure her release.

The woman also goes by the name Sandy Phan-Gillis, and is known as Pan Wanfen in Chinese.

The Chronicle said she was on a routine trip with Houston officials and businesspeople to China to promote trade with the Texas city.

She offers consulting services for U.S. and Chinese businesses, the newspaper said.