The World Anti-Doping Agency (WADA) subsequently requested an independent investigation from Swiss prosecutor Eric Cottier to look into the incident.
China said it would cooperate with the investigation after Wada also said he would send a compliance audit team to assess the country's anti-doping program.
In the women's 100m breaststroke semifinal, Asian Games gold medalist Tang Qianting won with a time of 1:04.68, setting her first regional record.
In the final the next day, she improved her time by 0.29 seconds and broke the record again. She was two seconds faster than second place Yang Zhang.
Tan, who is coached by former Canadian team member Pierre LaFontaine, was not one of the players who tested positive for TMZ.
The same was true for Pan Zanle, who won the men's 100m freestyle in 46.97 seconds, 0.17 seconds slower than his own world record.
It was the third time in Pan's career that he swam 100 meters in 47 seconds.
The 19-year-old also competed and won the 50m, 200m and 400m, setting a personal best time of 3:45.58 in the latter.
Wang Shun, who became the first Asian swimmer to win a gold medal in the men's 200m individual medley at the Olympics, topped that event in 1:55.35, making him his third-best time of all time.
Right behind him was Zhang Zhanshuo, who touched the field in 1 minute 58.97 seconds. But his standout performance came in the men's 800m freestyle, where the 16-year-old took first place with a new national record time of 7:47.84.
Yang Junxuan swam the women's 100m freestyle final in 52.68 seconds to win the gold medal and set a new national record.
Qin Kaiyeon, a four-time world champion and winner of six Asian Games gold medals, won the 100m breaststroke in 58.24 seconds.
Mr. Hata was also one of the people who tested positive.
Another person who tested positive for TMZ is 18-year-old Yu Yi-ting, a three-time Asian Games gold medalist.
Yu first touched the wall in the final of her favorite event, the 200m individual medley, with a time of 2:09.73, one second slower than the bronze medal she won at the World Aquatics Championships in Qatar in February. .
Olympic champion Zhang Yufei completed the women's 100m butterfly in 56.36 seconds, taking first place and qualifying for the Olympics.
Zhang was about 0.5 seconds ahead of Yu, who swam a personal best of 56.82 points.
One of the highlights of the 10-day event was 11-year-old Yu Zidi, who missed the Olympic qualifying time by two seconds in the 400m individual medley.
However, she achieved nine personal bests in swimming distances in the 10 events she competed in: freestyle, backstroke, butterfly and individual medley from 50 meters to 1,500 meters.
