SEATTLE -- It's been six months since Catherine Chan last spoke to her mother, 55-year-old Sandy Phan-Gillis. The Houston-based woman has been arrested and detained in China since March.
"My mother is being held prisoner in China," Chan said. "They told us that she is accused of stealing state secrets."
Phan-Gillis toured China on business as part of a trade delegation in March.
Chan said her mother was detained at the border on March 19. Today, she remains in detention there.
"My mom has very strong relationships with a lot of Chinese leaders and it's just shocking to know that they are accusing her of that," Chan said.
Sandy's family said her health is failing and, while the president of China tours Seattle, the city that Chan calls home, Chan is hoping her message reaches Chinese President Xi Janping.
"Breaks me inside that I don't know what to do for my mom or how to help her," Chan said.
Q13 FOX News asked the president's spokesman about Phan-Gillis during a news briefing in Seattle Tuesday night. He said he couldn't comment on her situation because he wasn't aware of it.
In a letter to President Barack Obama, Phan-Gillis' husband, Jeff Gillis, asks the State Department to help arrange the release of his wife. He denies that she is a spy or a thief.
Chinese authorities are investigating an American businesswoman on suspicion that she threatened China's national security, the Foreign Ministry said Tuesday.
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.