Law professor Tey Tsun Hang continued on the witness stand for a second day, as he recounted his version of events leading to the recording of his first three statements by anti-graft officers.
He told the court on Tuesday, that he was under strong psychoactive medication and in a "fragile state" when he was subjected to "brutalising tactics" by Corrupt Practices Investigation Bureau (CPIB) officers.
This, he added, happened on April 5 and April 10, when his statements were recorded at the CPIB headquarters.
Tey said he had signed the three statements without reading them thoroughly - for two of them, he was forced to later make amendments as dictated by the recording officer.
He referred to one statement as akin to a "dog's dinner", while another was given as a "silent protest of a victim of oppression".
Tey, a former district judge, also told the court that CPIB officer Wilson Khoo had made him miss a psychiatric appointment on April 10 to record a statement.
A trial within a trial is underway to determine if six statements Tey recorded by CPIB officers were made voluntarily and not under duress, and as such can be admitted in court as evidence.
The associate professor at the National University of Singapore, faces six charges of obtaining gifts and sex from former student Ms Darinne Ko Wen Hui, 23, in return for better grades.