Every year, Amnesty International publishes an exhaustive report looking at capital punishment around the world. Researchers from the activist group, which campaigns against the death penalty, sift through court records and news reports to document how many people were put to death in various countries.

This is no easy task. Many countries have opaque public records on executions, and the researchers are sometimes able to provide only minimum numbers or estimates. Other countries' execution totals can’t be estimated at all because of a lack of data.

For years, China has been one of those countries. In its most recent report, Amnesty explained that the number of executions carried out in China is considered a state secret by its government. Amen also suggested that there were possibly “thousands of executions carried out in China” in 2017 — far more than in any other country.

The secrecy surrounding the death penalty in China is back on center stage after a Chinese court on Monday sentenced a Canadian drug trafficker to death. Robert Lloyd Schellenberg, 36, a native of Vancouver, had been sentenced to 15 years in prison for his role in an organized drug-trafficking operation. His sentence was changed after a retrial.

Canada, which does not allow the use of capital punishment, condemned the decision. “It is of extreme concern to us as a government — as it should be to all our international friends and allies — that China has chosen to begin to arbitrarily apply a death penalty,” Prime Minister Justin Trudeau told reporters in Ottawa on Monday.

Schellenberg’s sentencing comes as diplomatic tensions run high between Canada and China. On Dec 1, Canadian authorities arrested Meng Wanzhou, the chief financial officer of Chinese tech giant Huawei, at the request of the United States. China has since detained a number of Canadian citizens.

The Chinese government also took the rare step of inviting foreign journalists to view the court proceedings against Schellenberg this month, suggesting that they were seeking a high level of media coverage.

But while Schellenberg’s case may be unique, executions for seemingly lower-level crime such as drug smuggling are certainly not. According to Amnesty’s 2017 report, China was among the small number of countries known to have executed people for drug-related crimes that year, alongside Iran, Saudi Arabia and Singapore.

Many foreigners have been executed for alleged drug offenses. In 2009, China executed a British businessman on allegations of smuggling heroin, despite the personal intervention of British diplomats and Prime Minister Gordon Brown, who claimed that Akmal Shaikh’s mental health had been overlooked. In 2017, a Colombian man was executed for drug smuggling.

The Chinese system is not known for its consistency or openness. A 2008 Washington Post investigation found that capital punishment was marked by “secrecy, lack of due process and uneven application of the law,” despite attempts at reform.

Human rights activists have argued that China’s suppression of information about executions dates back decades. Attempts by outside groups to track or estimate the number of executions have proved difficult: Amnesty stopped releasing estimates in 2009, accusing the government of misusing their statistics.

“Amnesty International always made clear that the figures it was able to publish on China were significantly lower than the reality, because of the restrictions on access to information,” the group’s 2017 report stated.

But there may be hope for greater transparency. The Dui Hua Foundation, a U.S.-based organization that tracks executions in China, estimated that 2,000 people were executed in 2016 — a very high number but still a substantial drop from 2002, when the group estimated that 12,000 people were killed. The foundation said the lower numbers may have been the result of a 2007 change that allowed China’s Supreme Court to review all death sentences.

Schellenberg has 10 days to appeal again, according to Chinese authorities. It is widely expected that a higher court will review his case before a death penalty is carried out.

Read more: