image captionMichael Spavor (L) and Michael Kovrig have been held since December 2018
Canadian diplomats say they have been not allowed to attend the trial in China of Michael Spavor, a Canadian businessman accused of espionage.
It is the latest in a diplomatic spat between China and the US and Canada.
Mr Spavor was arrested more than two years ago, along with fellow Canadian, former diplomat Michael Kovrig.
The detentions came days after Canada detained Meng Wanzhou, a senior executive at Chinese tech giant Huawei, on a US warrant.
Canada has accused China of conducting “hostage diplomacy”. Beijing denies the cases are linked.
On Friday morning a group of foreign diplomats gathered outside the court in Dandong, a city in northern China, after they were denied entry. Mr Spavor is thought to have already arrived at the court.
Among the group was the charge d’affaires of the Canadian embassy in China, Jim Nickel, who told reporters that it was a breach of international law to bar their entry.
He added that Canadian diplomats were also refused access to Mr Spavor before his trial, and that they were “disappointed by the lack of transparency and the lack of access”.
Mr Kovrig is due to go on trial next week.
Both Canadians have been held in prison since their arrest in December 2018. They were formally indicted in June last year, and face lengthy jail terms if found guilty.
Mr Spavor is a founding member of the Paektu Cultural Exchange, an organisation which facilitates international business and cultural ties with North Korea, while Mr Kovrig worked for the International Crisis Group think tank.
US President Joe Biden has publicly supported calls for the two men’s release and has pledged to work with Canadian Prime Minister Justin Trudeau to ensure “their safe return”.
In 2019 the founder of Huawei Ren Zhengfei – who is the father of Meng Wanzhou – claimed in an interview that her arrest was politically motivated.
media captionRen Zhengfei described the arrest of his daughter as politically motivated