Game of 'hostage politics'

China yesterday 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 Robert Lloyd 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.

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.

The timing and swiftness of Schellenberg's sentence, and the inclusion of new evidence presenting him as a key player in a plan to ship 222 kilograms (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".

Canadian Prime Minister  Justin 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 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."