A university student fell to his death from a nine-storey dormitory in Pathum Thani on Sunday night, and the body of a female student with multiple stab wounds was later found in his room along with messages scrawled in blood.

Emergency services were called to the dormitory on Sunday night. The dead man was later identified as a 30-year-old Chinese national, a first-year humanities student.

Around 10.30am on Monday, police were called back to the dormitory after a 21-year-old woman was found dead inside a room on the eighth floor.

The dead woman, also a first-year humanities student, was in the bathroom.

She had multiple stab wounds to her neck, head, chest and arms. A post-mortem examination found she had been dead from eight to 24 hours. The room showed signs of disturbance, wand a blood-stained knife was found on a desk near the door, police said.

Investigators also reported that several sentences written in English had been scrawled in blood on the walls of the room and bathroom. The messages suggested a need to leave and the importance of understanding over money. 

Police think the two students were in a relationship. A neighbouring student told investigators the young man had a loud phone argument with someone about two weeks ago.

Police suspect the couple had a serious argument during which the woman was fatally attacked with a knife. Investigators suspect the man then injured himself, wrote messages on the walls and later jumped from the room balcony.

The police investigation was continuing.