Within 72 hours of the start of the Paris Olympics, star Chinese swimmer Zhang Yufei had already climbed the champions’ podium twice. The former gold medalist won two bronzes as China fights to best rivals like the United States and Australia.

But the wins for Zhang, dubbed China’s “butterfly stroke queen,” have come under scrutiny – both from her legions of fans and the wider sporting world.

The Chinese team is at the center of a controversy that’s roiled international sport following revelations that nearly half the group Beijing sent to the Tokyo Olympics in 2021, including Zhang, had months earlier tested positive for a banned performance enhancing substance.

The swimmers had been cleared by China’s Anti-Doping Agency (CHINADA) shortly before the Tokyo Games, after it ruled that the positive tests for banned heart drug trimetazidine – believed to aid endurance and recovery time – were the result of contamination, likely from a hotel restaurant. The global sports doping watchdog World Anti-Doping Agency (WADA) accepted the assessment without an appeal.

But the situation, first reported by the New York Times and German public broadcaster ARD in April, has sparked backlash in the swimming world, where doping can result in years-long bans for athletes who violate the rules. The Times reported that Zhang was one of the swimmers who tested positive at the time.

Concern only deepened Tuesday, after WADA acknowledged a separate 2022 case in which two Chinese swimmers tested positive for “trace amounts of a prohibited substance metandienone,” a banned anabolic steroid. They were provisionally suspended but later cleared of a violation by CHINADA – again citing contamination linked to food, WADA said.

Since the 2021 case came to light, prominent athletes have voiced concerns about the anti-doping system. US Anti-Doping Agency chief Travis Tygart accused WADA of engaging in a cover-up and earlier this week said its failures had “overshadowed” the Olympics. The US government is separately pursuing a criminal investigation.

The furor has continued even after the release earlier this month of interim results from a probe into WADA’s handling of the 2021 case. The report, conducted by an independent investigator, backed the anti-doping body’s decision not to appeal the case. A separate audit by swimming governing body World Aquatics also said it found that body hadn’t mismanaged the case when it too decided not to appeal.

Deepening controversy

For China’s athletes, however, the pressure is apparent.

As races got underway this weekend, Zhang told reporters she was “deeply worried” that other athletes would view her through a “biased lens” and be reluctant to compete against her.

“I feel so wronged,” said Zhang, denying that Chinese swimmers engaged in doping.

And concerns about transparency within the anti-doping system continue to swirl, especially following the latest revelation.

The 2022 case, reported by the Times earlier this week, involves a swimmer on the Chinese roster in Paris, according to the paper.

WADA said in its statement that it had thoroughly reviewed that case, which it linked to two other positive tests from Chinese athletes in other sports earlier this year, and “concluded that there was no evidence” to challenge the Chinese finding that contaminated meat was the source of the positive tests. It noted that Chinese authorities had found the steroid in meat samples it tested.

The body also said it had been “unfairly caught in the middle of geopolitical tensions between superpowers” – in an apparent reference to the pushback it’s received from the US and its anti-doping agency.

In a statement CHINADA said the latest news report “distorted the fact(s) and quoted the relevant case out of context,” noting the “issue of meat contamination of prohibited substances is prevalent worldwide and similar cases have occurred in many countries and regions.”

Under pressure

In China, where the swim team has long been a source of Olympic glory, the situation has brought outrage and accusations of unfair treatment.

Chinese social media was flooded with an outpouring of support for Zhang over the weekend, as fans called for her not to be upset over a third-place finish Monday in the 100-meter butterfly. Zhang, who won silver in the event in Tokyo, was seen with tears in her eyes at the podium.

“Despite the immense pressure, the fact that you have won a medal is the best outcome,” wrote one social media user on the platform Weibo.

“It mirrors China’s continuous growth and revival, even as it faces encirclement and suppression from the West,” the post added, echoing a point made by many users who portrayed the latest controversy as orchestrated by the US.

“It’s high time to slam our fists on the table over the exclusive global drug system that the US has orchestrated,” said another.

At the heart of the outrage in China is the scrutiny the Chinese swim team has faced in Paris.

Earlier this month, global swimming body World Aquatics acknowledged the 2021 case had “weakened” community trust in its anti-doping system and pledged to test certain athletes “including Chinese athletes taking part in the Paris Olympic Games,” more frequently than others.

Last week, the body said Chinese swimmers have been tested more than those from all other countries, averaging 21 times per swimmer since the start of the year. That compares with an average of four times overs the same period for Australian swimmers and six times for Americans.

China’s Pan Zhanle, who took gold in the 100-meter men’s freestyle on Wednesday after smashing the world record, said he had been tested more than 20 times in the past few months. He said he didn’t feel “there was any difference or influence (on his performance),” since it was done according to the rules.

But some in China say the testing regime is hurting the team.

On Monday, retired two-time Olympic diving champion Gao Min pointed to Zhang’s bronze win and star swimmer Qin Haiyang’s seventh-place finish in the 100-meter men’s breaststroke.

“Something must have gone awry with the athletes’ pre-competition training. Personally, I believe that seven doping tests in one day might have disrupted our Chinese swimming team,” Gao wrote on Weibo.

A related hashtag received nearly 90 million views, with commentors claiming “unfair” treatment of China’s swimmers and even a conspiracy to disrupt the team’s medal tally by “affecting normal routine and training.”

“Why don’t you complain? Don’t athletes need a break?” said one comment with thousands of likes.

When questioned by a Chinese state media reporter about the testing regime at a briefing in Paris last week, a WADA official said the Chinese swimmers “should be happy that they can show that they’ve been tested so many times, therefore, hopefully the wrong allegations that are put against them can be disproven.”