Law prof Tey cross-examines ex-student Ko from the dock

The National University of Singapore law professor on trial for corruption in a sex-for-grades cross-examined his former student on Monday.

Tey Tsun Hang, 41, is accused of obtaining gratification in the form of gifts and sex, in exchange for lifting Ms Darinne Ko Wen Hui's grades. 

When Ms Ko took the stand, Tey questioned her in a gentle manner. 

She gave an account of the circumstances leading to the recording and her endorsement of her first statement made on April 2 last year.

Ms Ko said she was hauled in by two officers from the Corrupt Practices Investigation Bureau (CPIB), at about 7am or 8am during the examination period. 

She said she was deprived of sleep, felt scared and anxious, and was interrogated until about 7pm before she was brought to see CPIB's Deputy Director, Teng Khee Fatt. 

She said the recording officer had told Mr Teng she had been uncooperative. 

Mr Teng, she said, told her that the evidence she gave the CPIB was "not making out the elements of the charge against Tey". 

During their two-and-a-half-hour conversation, she said Mr Teng told her that corruption is a two-sided offence and that indemnity could be granted if the need arose. 

She also said Mr Teng had wanted her to write that she had given the gifts because she wanted "favour" from Tey but she refused. 

The two then argued about the terms to be used and finally settled on the words "undue prejudice", which she took as "treating her unfairly". 

"I was slightly more comfortable with that compromise even though it was still not an accurate depiction of the true state of affairs," said Ms Ko. 

When asked by Tey what was the true state of affairs, Ms Ko said: "I only bought Prof Tey the gifts because I liked him and we were in a relationship." 

But Mr Teng didn't buy this answer, she said. 

Ms Ko said he told her that it was not possible for a girl to buy a guy gifts. 

She said Mr Teng also insisted that the reason why she bought those gifts was so that Tey would show her favour vis-a-vis her grades.

Ms Ko said she was told she was not allowed to go home until the CPIB recorded a statement from her. 

When asked if the statement was accurate, Ms Ko said it wasn't. 

She said the inaccuracy pertained to her motivation for showering Tey with gifts. 

Earlier in the day, the Prosecution went through the impeached parts of the statements and evidence provided by Ms Ko. 

Lead prosecutor Andre Jumabhoy singled out differences in areas such as the time that Tey had called Ms Ko and revealed to her confidential ranking and grades before the release of the results. 

Ms Ko had told the CPIB that Tey had called at about 11am but told the court last week he called a few minutes before the official release of the results. 

Another area was the bill for the Garibaldi dinner, which she had paid. 

With impeachment, the judge will decide at the end of the trial which parts of evidence to take into consideration.