A psychiatric evaluation has been ordered for a 20-year-old freshman at Sichuan Normal University who is accused of killing his roommate.

Teng Gang allegedly used a kitchen knife to stab fellow student Lu Haiqing, 20, more than 50 times before decapitating him in a dormitory of the university's Chenglong campus in the Longquanyi district of Chengdu, Sichuan province.

Teng, who is said to have a history of mental illness, was detained at around 11.50 pm on March 27.

According to a report in China Youth Daily, the pair had been arguing the day before Lu's death.

A statement released by Teng's parents said their son was known to self-harm and had recently expressed suicidal thoughts.

The results of the psychiatric evaluation are expected by early next month, according to the father Teng Zongwu, deputy chief of Baiyin Prison's finance section in Gansu.