It remained unclear whether a broken heart or study-related stress drove Kittiphan Bamrung-karn, 24, to suicide.

He often told his mother that he was in love with a third-year student studying at the Faculty of Arts.

"His friends told me he was talking on the phone, like he was quarrelling with someone, before he suddenly sprang up and jumped to his death," Kittiphan's mother, Orn-uma, said tearfully.

She said her son did not show any signs he was about to do something dramatic when he talked to her at around 5pm on Tuesday. "He only said he was concerned about his health. I was shocked to find that he had killed himself," Orn-uma said.

She was also aware that Kittiphan had problems with his studies. The undergraduate course at the Chulalongkorn University's Faculty of Engineering usually takes four years. However, Kittiphan had yet to collect enough credits to qualify for the graduation at the end of this semester.

Assoc Prof Boonsom Lerthiranwong, CU vice president for students' affairs, said Kittiphan had needed special care since he was a first-year student.

"His way of thinking is not like others. He is among those students who are given one-on-one counselling with psychologists and psychiatrists," Boonsom said.

Kittiphan was allowed to stay at a dorm for this semester only.

According to police, witnesses saw the body of Kittiphan fall past the ninth floor of the dorm at around 11.55 pm on Tuesday.