It is the oldest rule in global relations: Don't jail another country's diplomats.

A former Canadian diplomat detained in China last month does not enjoy diplomatic immunity, a Chinese spokeswoman said Monday, rejecting a complaint from Prime Minister Justin Trudeau that the man's rights were being denied.

Friends of the two Canadian men currently detained in China tell Global News they can’t understand how the two might pose threats to national security.

China has said two Canadian men were detained on suspicion of "endangering national security."

China confirmed Thursday it has detained two Canadian men, raising the stakes in a three-way dispute over a Chinese technology executive facing possible extradition from Canada to the United States.