Soon after he was arrested on suspicion of raping a patient during a late-night consultation in 2015, a general practitioner told police that he had put his saliva onto his fingers before inserting them into the woman for an examination.

Wee Teong Boo, 67, told the High Court yesterday that saliva has "anti-bacterial properties", although he admitted there was no excuse for using spit as a lubricant during a digital examination.

On the 10th day of Wee's trial, the prosecution sought to highlight discrepancies between his statements and the version he gave in court.

He is charged with molesting the woman, then a student aged 23, at his Bedok clinic on Nov 25, 2015, and raping her on Dec 30, 2015.

In the statements - taken on Dec 31, 2015 and Jan 1, 2016 - Wee told investigators he had used his saliva as lubricant. In court, he testified that he had not used any lubricant.

Yesterday, Wee said his statements were the correct version.

This prompted Deputy Public Prosecutor Sharmila Sripathy-Shanaz to ask: "Isn't saliva full of bacteria?" Wee replied: "It has anti-bacterial properties."

Pressed for authoritative sources, the doctor said it was "general knowledge" and told the DPP she could do an Internet search.

But the DPP contended Wee's entire account of carrying out a digital examination to rule out pelvic inflammatory disease was a lie.

The DPP put it to Wee that he had raped the woman and feared his DNA would be found inside her.

That was why he concocted an "elaborate story" of conducting a digital check with ungloved fingers and saliva as a lubricant - to provide an explanation for any of his DNA that may be found, she said.

"You never did any digital examination," said the DPP, pointing out there was no mention of any examination of the woman's genital area in Wee's case notes. Wee disagreed.

The DPP also contended Wee's defence that he had erectile dysfunction was an "afterthought". Wee again disagreed.

Wee had consulted a urologist in private practice on Jan 5, 2016, three days after he was released from the police lock-up. "You were trying to find a way to get yourself out of a rape case," said the DPP.

In court, Wee said he was shocked to learn on Dec 31, 2015, that he was being accused of rape because he was suffering from erectile dysfunction.

But the DPP pointed to Wee's Jan 1, 2016 statement, in which he had replied "no" when asked point blank if he had erectile dysfunction. "So were you lying then or are you lying now?" she asked.

Wee replied that the condition did not bother him.

The DPP pressed on, asking if he had "selective memory". "It can happen to anybody," Wee replied.

Details of the woman's account of how Wee allegedly molested her were also revealed in open court when the DPP wrapped up her cross-examination. The woman had testified behind closed doors.

The DPP put it to Wee that the woman visited him for gastric discomfort, and while examining her abdomen, Wee told her there was a lump in her groin area. Wee then slid his hand into her underwear and touched her genitalia, while asking "OK?" She replied "OK" because there was no pain, the DPP said, adding that Wee continued touching her and asking her if it was OK.

The DPP put it to Wee that he was emboldened by what he had done to her on Nov 25 and that was why he raped her on Dec 30. Wee disagreed. The trial continues on July 10.