BEIJING (AFP) - Canada's foreign ministry confirmed Thursday that China has detained a second Canadian under what Beijing has said is suspicion of threatening its national security.

"We can confirm that a Canadian citizen, Michael Spavor, has been detained in China," the ministry said in a statement.

"We have raised this case directly with the Chinese authorities. The Canadian government is seized of this case and will continue to speak with the Chinese government."

Ottawa previously said it was informed that former Canadian diplomat Michael Kovrig was arrested in Beijing on Monday.

The two Canadians are "suspected of engaging in activities that threatened China's national security," Chinese foreign ministry spokesman Lu Kang said, without explaining if the cases are related.

Kovrig, who works for the International Crisis Group (ICG) think-tank, was being investigated by the Beijing bureau of state security, while the agency's office in northeast Liaoning province was handling the probe into Spavor, Lu said.

Spavor is a China-based business consultant who facilitates trips to North Korea.

He has met with its leader Kim Jong Un and arranged some of retired NBA star Dennis Rodman's trips to the country.

The detentions of the two Canadian nationals have fuelled suspicions China is retaliating against Canada's arrest of Meng Wanzhou, the chief financial officer of Chinese telecom giant Huawei, at Washington's request on allegations related to breaking Iran sanctions.

Meng was released on Can$10 million (S$10.3 million) bail by a court in Vancouver on Tuesday pending a US extradition hearing.

Her case has infuriated Beijing and shaken Canada's relations with China, which is itself embroiled in a trade war with the United States.