The prosecution has applied to impeach former civil defence chief Peter Lim Sin Pang, 52, and substitute certain parts of statements he gave to the Corrupt Practices Investigation Bureau (CPIB) last year.
An impeached witness is considered less credible and what he has said in court will be given less weight by the judge.
Deputy Public Prosecutor Tan Kiat Pheng read out several examples where Lim's testimony in court were inconsistent with his CPIB statements. One example was that Lim told the court that it was Ms Pang Chor Mui, 49, who had initiated oral sex with him. But in his statement to CPIB, he had said that he asked her for sex directly and drove straight to the Stadium carpark where the incident took place.
The application came on a day of intense cross-examination where Lim appeared agitated several times.