A Canadian couple living in a northeast China town close to the border with North Korea has been detained over suspected intelligence gathering and stealing military secrets, China's Xinhua News Agency reported Tuesday.

The Foreign Ministry confirmed the report, stating that Kevin and Julia Garratt "are under investigation for suspected theft of state secrets about China's military and national defense research."

According to the couple's son Simeon Garratt, who lives in Vancouver, the Garratts have lived in China since 1984, and moved to the town of Dandong in 2008, where they ran a coffee shop and pursued humanitarian work. 

"I just find this whole situation so crazy when pretty much all my parents have done for the last 30 years is dedicate their lives to helping people in China," Simeon Garratt told The Wall Street Journal. "My best guess is honestly some sort of miscommunication or misunderstanding and it led to my parents paying the price."

Meanwhile, he's been actively searching for more information through Twitter, tweeting the following in response to stories about his parents: 

But of course, China has kept mum on the goings-on in the investigation. The last known sighting of the Garratts was Monday evening around 6:30 p.m. local time, when they were heading to dinner. 

Though it's rare for Beijing to pull such an action—China-Canadian relations have historically been smooth as trade partners—the action comes after the Canadian government accused China last week of alleged hacking into the country's National Research Council, an accusation China's Foreign Ministry readily dismissed.

Still, the accusation may have stung. 

"I'm guessing that this might be retaliation for the Canadian claim that Chinese state actors broke into Canadian computer systems," Shi Yinhong, director of the Center of American Studies at Beijing's Renmin University, told Financial Times. "These mutual accusations of spying paint an ugly shadow on the picture of bilateral relations."

Canada's Department of Foreign Affairs, Trade and Development has released a statement, saying that "Canadian consular officials stand ready to provide assistance, as required." The country's C.B.C. News reported the Garratt's other son Peter, who lives with them in Dandong, has also been asked to come in for questioning