The president of the World Anti-Doping Agency (WADA) on Monday defended the body’s decision to clear 23 top Chinese swimmers who tested positive for a banned heart medication ahead of the 2021 Tokyo Olympics.

Nearly half the swim team participating at the Tokyo Games tested positive for a performance-enhancing drug seven months earlier, a New York Times investigation found. The Chinese swimmers involved went on to win medals, including three golds.

The athletes said they accidentally ingested trimetazidine (TMZ) from contaminated spice containers and were cleared by Chinese anti-doping authorities, with WADA accepting their conclusions. Neither regulator disclosed the findings, leading to allegations of a cover-up in a documentary aired Sunday by German broadcaster ARD.

“We had no evidence of wrongdoing,” WADA President Witold Banka told reporters at a news conference Monday. “If we had to do it over again now, we would do exactly the same thing.”

Athletes cited in the report, including two-time Olympic gold medalist Zhang Yufei, are expected to compete for China in the upcoming Paris Olympics.