Peter Garratt, who lives in Dandong, China, with Kevin and Julia Dawn Garratt, said in an email to CBC News that he received a call from the State Security Bureau in Dandong asking him to come in.
"They also asked me to pick up some clothes and toiletries for them, so I assume they are at the bureau," he wrote.
Kevin and Julia Dawn Garratt were identified as suspects by the official Xinhua news agency in a brief report on Monday. Xinhua said the State Security Bureau of Dandong city in northeast Liaoning province was investigating the case, adding it involved the stealing of state secrets.
China's Foreign Ministry said the Canadian Embassy in Beijing was notified on Monday and that the couple's
"various rights have been fully guaranteed."
"Kevin Garratt and his wife ... are suspected of collecting and stealing intelligence materials related to Chinese military targets and important Chinese national defence scientific research programs, and engaging in activities that endanger China's national security," the Foreign Ministry said in a short statement.
'It sounds ridiculous'
In an earlier, on-air interview with CBC News Network, Peter Garratt said he had last heard from his parents more than 24 hours earlier, when they texted him about going out for dinner. He said the accusations against his parents are the first signs of any problems they've had during their decades in the country, where they moved in the mid-1980s to teach English. They now own a coffee shop in Dandong, a city near the border with North Korea.
"It sounds ridiculous," Peter Garratt said. "Military secrets? It sounds like something out of a movie or something. Those are the accusations, but I have no idea where they are coming from or how it even came about.”
Peter said he has spent most of his life in China and when he heard the news Tuesday, he thought it was a joke.
"I know that I’m being watched because my phone isn’t working properly, my email, everything’s been acting up weird, even my Skype, but I have nothing to hide so I’m not worried about anything," he said.
China's state secrets law is notoriously broad, covering everything from industry data to the exact birth dates of state leaders. Information can also be labelled a state secret retroactively. In severe cases, the theft of state secrets is punishable with life in prison or the death penalty.
'I didn't think it was real'
Simeon Garratt, one of the couple's sons who was raised in China and currently lives in Vancouver, also spoke with CBC News on Tuesday.
He only learned of the investigation after receiving messages from friends on various social media networks expressing concern and links to local media reports, he said. Believing at first the messages were spam, he called his brother Peter, who confirmed he had not heard from his parents for some time.
"I didn't know how to react, to be honest. I didn't think it was real," he said.
Simeon Garratt told CBC News he has spoken with the Canadian Embassy in Beijing and with representatives at the Foreign Affairs Department in Ottawa, but couldn't tell him "much more than I already knew."
Foreign Affairs said Monday it is trying get more information. The department said consular officials are ready to provide assistance.
"We are aware of reports that two Canadians have been detained in China. We are gathering information and monitoring developments closely," the statement said. "To protect the private and personal information of the individuals concerned, further details on this case cannot be released."
The family has yet to receive any word on whether formal charges will be laid, but Simeon Garratt called the news of the investigation concerning, because Chinese authorities "don't need a reason to do what they want to do."
"The possibilities start running through your mind."
The suggestion that his parents may have been involved in the theft of state secrets is "absolutely absurd," he continued.
"I think a lot of this has been blown out of proportion."
Uneven relationship between Canada, China
Last week, Canada blamed Chinese hackers for infiltrating computers at the National Research Council of Canada, something the Chinese Embassy in Ottawa denied.
A spokesperson for Foreign Affairs Minister John Baird said the minister took up the matter with Chinese officials in Beijing during his visit to Asia.
Prime Minister Stephen Harper's government has had an uneven relationship with Beijing since taking power in 2006.
Citing human rights concerns, Harper initially kept his distance from China. Under pressure from business in Canada, he sought to reach out to Beijing.
China is Canada's second most important trading partner after the United States, and bilateral trade is growing. Total
Canada-China trade was $69.8 billion Cdn in 2012 and $72.9 billion in 2013, according to official Canadian data.
In July, Chinese prosecutors charged British corporate investigator Peter Humphrey and his American wife Yu Yingzeng
for illegally obtaining private information. The couple was detained last year following work the two did for the British
drugmaker GlaxoSmithKline Plc (GSK), and their trial is set to start this Friday in Shanghai.