China on Tuesday vociferously defended a court's decision to impose the death penalty on a convicted Canadian drug smuggler, escalating a diplomatic row that experts say has descended into a high-stakes game of "hostage politics".
China's foreign ministry blasted Canadian Prime Minister Justin Trudeau's "irresponsible remarks" after he criticised the death sentence imposed on 36-year-old Robert Lloyd Schellenberg.
Beijing and Ottawa have been squabbling since last month, when Canada arrested the chief financial officer of top Chinese telecom company Huawei on a US extradition request related to Iran sanctions violations.
In a move observers see as retaliation, Chinese authorities detained two Canadian citizens -- a former diplomat and a business consultant -- on suspicion of endangering national security.
Then authorities revisited the little-known case of Mr Schellenberg, who was sentenced to 15 years in prison in November for drug offences.
A month later, an upper court took up his appeal and ordered a hasty retrial in the northeastern port city of Dalian after ruling that the punishment was too lenient.
The timing and swiftness of Mr Schellenberg's sentence, and the inclusion of new evidence presenting him as a key player in a plan to ship 222 kilogrammes (490 pounds) of methamphetamine to Australia, raised suspicion among observers.
"Playing hostage politics, China rushes the retrial of a Canadian suspect and sentences him to death in a fairly transparent attempt to pressure Canada," Human Rights Watch executive director Kenneth Roth said in a tweet.
Donald Clarke, a George Washington University professor specialising in Chinese law, coined an even grimmer term for the situation: "death threat diplomacy".
"The Chinese government is not even trying to pretend that there was a fair trial here," he said.
Prime Minister Trudeau expressed "extreme concern" that China had "chosen to arbitrarily" apply the death penalty.
But Chinese foreign ministry spokeswoman Hua Chunying denied Beijing had politicised Mr Schellenberg's case, calling on Canada to "respect China's judicial sovereignty... and stop making such irresponsible remarks."
Ottawa had issued a new travel advisory urging citizens to "exercise a high degree of caution in China due to the risk of arbitrary enforcement of local laws."
Hua countered: "Canada should remind its own citizens to definitely not engage in drug smuggling in China".
The court in Liaoning on said its actions were "in compliance with the provisions of the Criminal Procedure Law," the state-run Legal Daily reported.
China executes one or two foreigners every year -- nearly all for drug offences, according to John Kamm, director of the US-based Dui Hua Foundation rights group.
Experts said retrials are rare in China, especially ones calling for a harsher sentence, but rights groups note that courts are not independent and can be influenced by the ruling Communist Party.
"What's unusual is how this case shifted from extremely slow handling to suddenly rapid fire movement," said Margaret Lewis, a law professor at Seton Hall University.
The rare decision to allow three foreign journalists, including one from AFP, to attend the hearing makes it "clear that the Chinese government wants (the) international spotlight on this case."
"The timing is suspect and certainly his nationality makes it all the more glaring," she said.
Mr Schellenberg, who claimed he was innocent and framed by an acquaintance, has 10 days to appeal to the same high court that rejected his first appeal.
Ms Lewis said the court was likely to confirm the sentence and the case would move up to the Supreme People's Court.
The top court could confirm the death penalty, give him a two-year suspended death sentence that would be converted into a long prison term or reduce his punishment, she said.
Mr Clarke said: "My prediction is that the Supreme People's Court will sit on the review decision for as long as Meng's fate remains undetermined."
The fate of the other two Canadians, who have been held in undisclosed locations, remains a mystery.
Last week, Mr Trudeau accused China of "arbitrarily and unfairly" detaining former diplomat Michael Kovrig and business consultant Michael Spavor, who were rounded up nine days after Canada arrested Huawei executive Meng Wanzhou.
The Chinese foreign ministry rejected Mr Trudeau's assertion that Mr Kovrig, who now works for the International Crisis Group, still enjoyed diplomatic immunity.
Ms Meng, meanwhile, was granted bail by a Canadian court last month, allowing her to wait for the US extradition hearing in a Vancouver house.
Beijing on Tuesday repeated its calls for her immediate release, calling on Canada to correct its "severe mistake".