Canada said on Thursday it was monitoring developments closely after China indicted a Canadian citizen detained since 2014 on charges of spying and stealing state secrets.
Kevin Garratt was detained in August 2014 near China's sensitive border with North Korea along with his wife, who was also detained for months before being released last year.
Xinhua state news agency said Garratt was indicted in Dandong, a city in China's northeast where the Garratts had operated a cafe since 2008.
"During the investigation, Chinese authorities also found evidence which implicates Garratt in accepting tasks from Canadian espionage agencies to gather intelligence in China," Xinhua reported.
The Garratts ran a Christian coffee shop on the sensitive border with North Korea. China strictly regulates religious activities within its borders but its Foreign Ministry said on Friday that the case had nothing to do with Garratt's faith.
"China's judicial authorities will handle the case strictly according to law and Kevin Garratt's legal rights will be fully guaranteed," ministry spokeswoman Hua Chunying told reporters.
The case has inflamed tension between Ottawa and Beijing. The arrest happened less than a week after Canada accused Chinese hackers of breaking into a key computer network.
"Canada finds the indictment of Kevin Garratt by China concerning," said foreign ministry spokesman Francois Lasalle.
The indictment was announced the day after Canadian Prime Minister Justin Trudeau and senior cabinet ministers attended a lavish party in Ottawa hosted by China to mark the 45th anniversary of the establishment of diplomatic relations.
Diplomatic ties began under former Prime Minister Pierre Trudeau, Justin Trudeau’s father. China invited Justin Trudeau for a state visit shortly after he won power in October.
Garratt's son, Simeon Garratt, a Vancouver resident, said he was waiting for an update from his family's legal team in China.
"We don't really have any more word on it other than that. We haven't had access to anything to this point. It's a waiting game to be honest," Garratt said in an interview.
He said his mother was still not able to leave China. Julia Garratt was released in February but barred from leaving.
James Zimmerman, a Beijing-based lawyer for the Garratt family, declined to comment and said he was waiting to receive official documents from the court.
Brock University professor Charles Burton, a former Canadian diplomat who served two tours in China, said the indictment could signal the start of a process to expel the couple.
The main opposition Conservative Party demanded Ottawa act to secure Garrett's release.
"It is the height of irony, that as the Prime Minister ... (was) celebrating with Chinese diplomats at an event in Ottawa last night, Kevin Garratt sat in a Chinese jail," it said in a statement.