China has arrested a third Canadian amid a diplomatic spat between Beijing and Ottawa over the arrest of a Chinese telecom executive, a Canadian official said Wednesday.

"Global Affairs Canada is aware of a Canadian citizen detained in China," ministry spokeswoman Maegan Graveline told AFP, without providing further details.

A government source said "there is no reason to believe that this case is linked to (two) other recent cases of Canadians detained in China."

Earlier Chinese foreign ministry spokeswoman Hua Chunying told a regular press briefing that she had "not heard" about the detention first reported by Canada's National Post.

The recent detentions of a Canadian former diplomat and a Canadian entrepreneur has raised suspicions that Beijing is holding them in retaliation for Huawei chief financial officer Meng Wanzhou's December 1 arrest, though no link has officially been made between the cases.

Meng was released on bail last week in Vancouver pending a U.S. extradition hearing on U.S. fraud charges related to sanctions-breaking business dealings with Iran.

China has accused the other detainees -- former Canadian diplomat Michael Kovrig and China-based business consultant Michael Spavor -- of activities "that endanger China's national security."

They were both detained on December 10.

Kovrig took an unpaid leave from his diplomatic post last year to work as a Hong Kong-based senior adviser at the International Crisis Group think tank, while Spavor facilitates trips to North Korea and helped former NBA star Dennis Rodman travel to the neighbouring country.

Beijing has threatened Canada with "grave consequences" if Meng was not freed and Chinese state-run media has lashed out at the arrest, saying it was politically motivated.

Ottawa has repeatedly said the arrest was not political but rather a judicial process in keeping with an extradition treaty with Washington.