A Vancouver woman detained in China along with her husband on suspicion of stealing state secrets has been released on bail, the Chinese Foreign Ministry said Thursday.

Ministry spokesman Hong Lei said Julia Garratt was released while the case remains under investigation. She and her husband Kevin were detained on Aug. 4 by the state security bureau in China's northeastern city of Dandong, which borders North Korea.

CBC correspondent Andrew Lee, reporting from Beijing, said he had been texting with one of the Garratts' sons, Peter, who is in Dandong. Lee said Peter Garratt requested privacy so he can spend a few quiet days with his mother.

The detention of the Garratts came amid a crackdown on Christian groups aiding North Korean refugees along the border.

Hong said both have been charged with stealing secrets and spying and Kevin Garratt has been moved from residential surveillance to the more serious status of criminal detention.

"Kevin Garratt and Julia Garratt are under suspicion of undermining China's state security," Hong said. "Competent Chinese authorities will handle the case and ensure the legal rights of the two persons according to law."

Kevin and Julia Dawn Garratt, shown here flanked by their son Peter and daughter Hannah, are being investigated by Chinese authorities for allegedly stealing state secrets. The Canadian couple own a coffeeshop in Dandong, a Chinese city that sits adjacent to the North Korean border. (Simeon Garratt)

The Garratts, from Vancouver, have lived in China since 1984 and since 2008 ran a popular coffee shop in Dandong and conducted Christian aid work for North Koreans. They are in their mid-fifties.

The Canadian Embassy in Beijing referred questions about the case to spokesmen in Ottawa. Canadian diplomats say they've had regular consular access to the Garratts and have raised their case with high-level Chinese officials.

"While we welcome the recent decision to release Julia Garratt, the government of Canada remains very concerned with the detention of Mr. Garratt," said Erica Meekes, a spokesperson for Lynne Yellich, the minister of state for consular affairs. "We have raised the case at the highest levels and will continue to raise it with senior Chinese officials."

Shortly after the couple were detained, another of their sons, Simeon Garratt, told The Associated Press he knew of "no possible scenario I can think of that makes it plausible" that his parents would be stealing state secrets about military and national defence research.

The couple worked with North Star Aid, whose website said the British Columbia-registered charity seeks to help North Koreans primarily through providing humanitarian aid. Simeon Garratt said his parents made no secret of their faith but did not flaunt it in China, where proselytizing is against the law.

The accusations against the couple last August came about a week after Canada accused a China-sponsored hacker of infiltrating Canada's National Research Council, the country's top research and development organization.

China's Foreign Ministry expressed strong displeasure over that allegation.