The student, Mr David Hartanto Widjaja said he wanted to discuss his final year project, due for submission at the end of March. He wanted to give the lecturer a thumbdrive containing a computer program he had worked on.

Associate Professor Chan, 45, turned around for a moment to look at the thumbdrive. He explained to Mr Widjaja that the program could not run on his office computer as it needed special software.

As he had a deadline to beat, Prof Chan suggested that Mr Widjaja give him an oral overview instead.

The lecturer's version of what then happened was heard for the first time on Thursday on the second day of the coroner's inquiry into Mr Widjaja's death.

Prof Chan, a lecturer at the School of Electrical and Electronic Engineering, recounted how he was attacked by his student, who later fell four storeys to his death on campus grounds.

He told the court that he continued working at his computer, with his back to Mr Widjaja, while questioning the student. His replies sounded shaky and nervous, Prof Chan said.

Suddenly he felt something hitting his back, 'as if someone was punching me'. He told the court: 'I was asking myself: 'What's this? He's hitting me? Why?'

Prof Chan said he turned around to see a knife being thrust at his face. He was not able to tell the court which hand Mr Widjaja had it in, or how he had held it.

Prof Chan said he twisted his body to one side to avoid the blow and fell off his chair onto the floor.

Read the full story in Friday's edition of The Straits Times.