SINGAPORE — Contrary to her testimony last week that she was coerced into making parts of her first statement to the Corrupt Practices Investigation Bureau (CPIB), the officer who took Ms Darinne Ko’s statement said the 23-year-old appeared “calm”, “forthcoming” and “cooperative” that day.

And when Ms Ko — the key witness in former National University of Singapore law professor Tey Tsun Hang’s sex-for-grades trial — appeared tired during the recording of her statement, she was offered a break but she refused one, said CPIB Senior Special Investigator Png Chen Chen yesterday.

Tey, 41, is accused of obtaining gratification in the form of gifts and sex from Ms Ko, in exchange for better grades.

A district court yesterday heard that Ms Png began recording Ms Ko’s statement at 9pm on April 2 last year, almost 12 hours after she was picked up by CPIB officers from her Bukit Timah home.

When Deputy Public Prosector Koh Shu-En asked why Ms Ko’s statement was not taken earlier, Ms Png replied that they were trying to gather more information from her and to recover the exhibits and gifts she had mentioned earlier. These items included an iPod, a watch, shoes and a pen.

Ms Png said it took five hours to record the statement as there were “certain events and dates” that Ms Ko needed “some time to recall”.

The CPIB officer added she would clarify with her if she was in doubt about any event.

Ms Png testified that Ms Ko appeared to be “tired”, but the investigator said she would constantly check with Ms Ko if she needed a break. Ms Ko, however, said she did not need one. As Ms Ko was cooperative, she did not have “any difficulties recording” her statement, said Ms Png.

When she finished recording her statement, Ms Ko made some amendments and told Ms Png that she did not wish to testify in court. Ms Png told her to write that down in the statement.

Earlier yesterday, Ms Ko stood down as a witness in the trial, after four days on the witness stand.

Tey, a former district judge, produced cheque book entries and claimed he had paid for the gifts and dinner bill which he allegedly received from Ms Ko. Tey claimed he issued a cheque for S$2,500 in July 2010, and the amount was slightly more than the value of the gifts mentioned in four of the six charges he faces.

Ms Ko, however, said that no such cheque was given to her. Tey alleged that he had made out the cheque to Ms Ko, but she did not encash it and hence he paid her in cash.

The trial continues today.