Canadian couple living in a city close to China's border with North Korea are under investigation for the suspected theft of state secrets, state media said Tuesday.

Kevin and Julia Garratt, who run a cafe in the northeastern city of Dandong, are suspected of stealing information about China's "military and national defense research," according to a brief report released by China's official news agency Xinhua.

It is not clear whether the pair have been detained. Calls to their café, Peter's Coffee House, were not answered on Tuesday morning.

Xinhua said that the State Security Bureau in Dandong was investigating the case.

Officials at the Ministry of Public Security in Dandong, when contacted by CNN, said they were not aware of the situation.

The couple had been living in China since 1984 and had been running the coffeehouse, named after their youngest son, since 2008, according to Canada's Globe and Mail newspaper.

The Canadian Embassy in Beijing said it was aware of the reports and consular officials stood ready to provide assistance if required, it added.

"We are gathering information and monitoring developments closely," a spokesperson said in an email.

The cafe's website says it's "only meters from the border of North Korea and Dandong's Friendship Bridge" and a "perfect stop off while en route or returning from the Hermit Kingdom."

The cafe also held a weekly "English corner" to helps locals wanting to practice their language skills.

The investigation comes at a time of strained ties between Beijing and Ottawa after the Canadian government last week publicly blamed China for hacking government computers, the Globe and Mail reported.

(CNN)