China is investigating a Canadian couple who ran a coffee shop on the Chinese border with North Korea for suspected theft of military and intelligence information and for threatening national security, China's Foreign Ministry said yesterday.

The official Xinhua news agency identified the two as Kevin Garratt and Julia Dawn Garratt. In a brief report, 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.

Neither the Foreign Ministry nor Xinhua said if the couple had been detained, although the ministry said the Canadian embassy in Beijing was notified on Monday and that the couple's "various rights have been fully guaranteed".

Canada's Globe and Mail newspaper said the Vancouver couple had been living in China since 1984 and had opened a coffee shop called Peter's Coffee House in Dandong, a key gateway to reclusive North Korea, in 2008. The couple previously worked as teachers in southern China.