Former senior Central Narcotics Bureau chief Ng Boon Gay was accused of fabricating evidence, as the prosecution resumed its cross-examination in the closely-watched corruption trial on Thursday.

Deputy Public Prosecutor Tan Ken Hwee challenged whether several instances of sexual trysts between Ng and former IT sales manager Cecilia Sue between August 2010 and July last year, really happened.

Ng, who also used to head the Criminal Investigation Department (CID), had listed these instances of oral sex at carparks at Dempsey Road and East Coast Park on Monday, when he first took the stand.

He maintains that he was having an ongoing affair with Ms Sue from 2009. But the prosecution's position is that, based on her statements to anti-graft officers, the couple broke up soon after she gave birth in May 2010.

Ng, 46, faces four charges of obtaining oral sex from Ms Sue in exchange for furthering the business interests of her firms.