Robert Lloyd Schellenberg, 36, nodded as the judge in the northeast city of Dalian asked him whether he understood the verdict, following a day-long retrial in which he declared his innocence.

"The court completely rejects the accused person's explanation and defence because it is completely at odds with the facts," the chief judge said in a courtroom packed with observers -- among them Canadian embassy officials and three foreign reporters, including one from AFP.

He can appeal against the sentence at an upper court.

Schellenberg had originally been sentenced to 15 years in prison and a 150,000-yuan ($22,000) forfeiture in November. But following an appeal, a high court in Liaoning ruled in December that the sentence was too lenient given the severity of his crimes.

"I am not a drug smuggler. I came to China as a tourist," Schellenberg, said in his final statement before the sentence was announced. He was brought to the hearing in handcuffs.

The sentence comes against the backdrop of the Chinese government's anger over the arrest in Canada of a top executive from telecom giant Huawei last month on a US extradition request related to Iran sanctions violations.

Chinese authorities have since detained two Canadian nationals -- a former diplomat and a business consultant -- on suspicion of endangering national security, a move seen as retaliation over the Huawei executive's arrest.

The Dalian court said Schellenberg, who was detained in December 2014, played a "key part" in an international drug trafficking syndicate.

"Not just content with spreading drugs in one country, the syndicate has spread across borders... it is a harm to human health and also to the stability of countries," the court said.

- China denies political link -

China has executed other foreigners for drug-related crimes in the past, including a Japanese national in 2014 and a Filipina in 2013.

Experts said retrials are rare in China, especially ones calling for a harsher sentence.

Ottawa has said it was following the case "very closely" and has provided Schellenberg with consular assistance.

Beijing has repeatedly denied any diplomatic pressure in the case.

The Chinese foreign ministry said Friday critics "can stop recklessly suspecting others of politicising legal issues just because they have done so".

Canadian Prime Minister Justin Trudeau has accused China of "arbitrarily and unfairly" detaining former diplomat Michael Kovrig and business consultant Michael Spavor.

Trudeau suggested that Kovrig still enjoyed diplomatic immunity, an assertion rejected by the Chinese foreign ministry on Monday.

- No coins in court -

The Dalian court was filled with about 70 observers, who were patted down and made to empty pockets -- receipts and stray coins were to be left at the security check.

In an opening statement, Schellenberg said he had come to China after travelling through Southeast Asia, including Laos, Myanmar, Malaysia, Singapore and Thailand.

He said a friend recommended a man named Xu Qing as a translator and he was swept up in what has turned out to be an international drug trafficking syndicate.

"This is a case about Xu Qing, he is an international drug smuggler and a liar," Schellenberg told the court, accusing Xu of setting him up.

Schellenberg claimed the drug deal was masterminded by Khamla Wong, a Canadian who was arrested in Thailand in 2016 on drug charges.

But Chinese prosecutors said Schellenberg was the principal suspect in a case involving an international syndicate that planned to send some 222 kilogrammes (490 pounds) of methamphetamine to Australia, hidden in plastic pellets which were concealed in rubber tyres.

Prosecutors brought in Xu as a witness, who in close to two hours of testimony never once turned to look at Schellenberg.

When pressed on details, he frequently said he could not remember and to refer to a written statement for details, including when Schellenberg questioned him about 180,000 yuan he was purportedly given.

Two other Chinese men have been involved in this case -- one was sentenced to life imprisonment, another handed a suspended death sentence.