A postgraduate student at Xiangya Hospital of Central South University in Changsha, Hunan province, was found dead on Sunday after going missing following a night shift, prompting an official investigation into the circumstances of her death.

The student, surnamed Sun, left her dormitory at 9:57 pm on Saturday and was subsequently reported missing, according to a statement from the Hunan Provincial Health Commission. The university immediately organized a search, alerted authorities, and contacted the student's family.

At 11:26 pm, police informed the hospital that an individual had jumped into the river near the Juzizhou Bridge in Changsha, and rescue operations were underway. A body was recovered around 4 pm on Sunday and was confirmed to be Sun.

"We are deeply saddened and grieved by the unfortunate passing of the student and will assist the family with the aftermath," the statement said.

The university and the health commission have established a joint investigation team to conduct a probe into online allegations in accordance with regulations and laws, the statement said.

Media reports indicate that Sun left a message before she went missing, referring to her "last night shift", while mentioning that tasks assigned by her supervisor, surnamed Gu, were interfering with her standardized residency training.

On Tuesday, the online outpatient appointment system at the hospital showed that Gu, a deputy chief physician in the neurology department, had been suspended from her clinical duties.