A high school physics teacher in southern China has been detained by police and expelled from the Communist Party of China following allegations that he previously sexually assaulted a teenage student who recently died, authorities said.

Tang, who taught at Baise Clifford Senior High School in the Guangxi Zhuang autonomous region, was taken into custody after a preliminary investigation, according to a joint statement released on Tuesday night by local education, public security, discipline inspection and other relevant departments.

The incident came into the limelight on Monday after an anonymous report surfaced online accusing him of sexually harassing and assaulting Fu, a student under 16. The report quickly drew widespread attention on social media.

Fu's cousin, identified only by her surname Nong, told reporters that Fu, born in 2002 in Napo county, Baise city, was a top student when she entered the high school in 2017. Tang was her head teacher.

The report alleges that from 2017 to 2020, Tang subjected Fu to prolonged sexual abuse and harassment using manipulative tactics, fabricating what appeared to be a romantic relationship. Fu meticulously documented the alleged abuse in her diary, Nong said.

Fu was 15 when she was first manipulated by Tang, causing her severe emotional distress, self-harm and a loss of hope, Nong said. Despite her academic excellence and achievements, the toxic relationship with Tang caused Fu to abandon her college entrance exams in 2020.

She managed to resume studying for entrance exams in 2021, and was admitted to East China Normal University. However, recurring depression hindered her studies and ultimately led her to drop out, Nong said.

On Feb 5, 2023, Fu exposed Tang's actions in a class chat group, but Tang immediately disbanded the group, Nong said.

Nong said that between 2018 and 2024, Fu was rescued multiple times after attempting suicide and underwent several rounds of mental therapy. Recurring illness led to severe depression, and Fu took her own life on Jan 17 this year, Nong said.

Nong said Fu's family discovered evidence in her phone records, diary and conversations with classmates while sorting through her belongings.

The case is currently under further investigation.

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