Chinese sports authorities have issued a coordinated response condemning online abuse and toxic fan culture after three-time Olympic gold medalist Quan Hongchan was targeted by cyberbullying and misinformation, vowing legal action and stronger protections for athletes.

In separate statements released on Wednesday, the Ersha Sports Training Center of Guangdong and the swimming management center of the General Administration of Sport of China said they had launched investigations into the incident and reported relevant cases to police.

The Guangdong-based Ersha center said Quan — who has brought national honor through her achievements — had endured "undue public pressure and psychological harm" amid the online attacks.

It warned that malicious defamation, abusive language and the spread of false information targeting athletes and their families had crossed legal and ethical red lines, disrupting training and daily life while eroding the integrity of the sporting environment.

The national swimming authority confirmed it is working with local sports officials to verify and address the situation, pledging a zero-tolerance approach.

"No matter who is involved, once verified, they will be dealt with seriously without leniency," the statement said. It also outlined plans to strengthen athlete protection systems, including mental health support, and to safeguard a "clean and healthy" public discourse around sport.

Both bodies explicitly denounced the encroachment of so-called "fan circle" culture into athletics, saying its more extreme forms have harmed athletes' well-being and the image of national teams. Authorities signaled that regulatory and legal measures would be used to curb such behavior.

Public attention intensified following a recent interview in which Quan became visibly emotional while reflecting on the aftermath of the Paris Olympics.

She revealed that weight fluctuations and sustained public scrutiny had at one point pushed her to consider retirement. Prolonged anxiety led to insomnia and recurring nightmares, including dreams of falling from the diving platform.

Quan, 19, also appealed for restraint online, urging critics to stop targeting her family and friends. "Otherwise, they all distance themselves from me," she said.

Authorities said investigations are ongoing, with the Ersha center pledging to pursue legal accountability for those responsible. They also called on the public to avoid spreading unverified information or engaging in personal attacks, and to refocus attention on athletic performance and the core values of sport.