Two Canadians detained in China after the arrest of a Chinese Huawei executive in Canada are marking one year in detention, with supporters accusing Beijing of using them as diplomatic hostages.

Michael Kovrig, a human rights NGO worker and ex-diplomat, and Michael Spavor, a North Korea-focused consultant, were detained by Chinese authorities on December 10 last year.

They were charged with espionage in what supporters said was Beijing’s revenge for the arrest in Canada of Meng Wangzhou, chief financial officer of Chinese communications company Huawei.

US prosecutors want Ms Meng extradited from Vancouver, where she is on bail, so she can face fraud charges.

International Crisis Group, the NGO Mr Kovrig works for, said: “It is clear that he is merely a pawn in a larger geopolitical game.”

Mr Spavor’s family released a statement saying: “Michael is an earnest, genuine, and impossibly fun person, who we believe has been detained in error. He deserves better, as does fellow Canadian Michael Kovrig. We call on all sides to work towards a quick and positive resolution that results in their release.”

The Canadians have been interrogated, spending periods in rooms with lights switched on 24 hours a day.

Acquaintances of Mr Spavor told The Telegraph that despite such conditions, he had been able to read in custody and work on Chinese language skills.