A man on trial for raping his mother told the High Court yesterday that he had been slapped and threatened before he gave two "untrue" statements on the day of his arrest, an allegation firmly refuted by the two police officers in question.

The Criminal Investigation Department officers - Deputy Superintendent (DSP) Burhanudeen Haji Hussainar and Inspector Thinagaran Krishnasamy - interviewed the accused for two hours before he was handed back to the investigating officer for his statement to be recorded on Oct 4, 2013.

The 33-year-old accused, who has a chronic ear infection, alleged that when he denied raping his mother, Insp Thinagaran slapped him twice on his left ear until pus oozed out and then pushed him against a wall.

He said that DSP Burhanudeen told him: "No mother would come to a police station to complain that her son raped her." The accused said he then raised his voice and retorted: "If you have evidence against me, I would accept the charges."

After saying this, he was slapped on the back of his head and neck by Insp Thinagaran, he alleged.

"I begged them to stop beating me," he said. He said DSP Burhanudeen threatened more beatings if he did not cooperate with the investigating officer, Assistant Superintendent (ASP) Thermizi Tho, who recorded his two statements.

He said he complained about the beating to ASP Tho but the officer told him they were in "his team". He said he gave the two statements because he felt helpless, was in pain and wanted to be granted bail.

While the contents of the statements have yet to be disclosed in court, the accused said that he felt so helpless at the time that he "imagined some porn story", before his lawyer Andy Lem stopped him from elaborating further.

Both officers took the stand and denied the accused's allegations.

Asked if he had offered any threat, inducement or promise to the accused, Insp Thinagaran replied: "Your Honour, I only offered him a drink."

Dr Wong Kia Boon, who examined the accused before and after his statements were taken, testified that the man answered no when asked if he had been handled roughly by the officers. To this, the accused said he chose not to reveal the assault as he believed the doctor was part of the "team".

The man is accused of raping and molesting his mother, then 53, after he returned home at about 2.30am on Oct 4, 2013.

When he took the stand in July, he denied the charges, although he admitted to having lifted up her nightdress while she was asleep.

On Wednesday, he challenged the admissibility of the two statements, claiming he had been threatened into giving them. The trial continues.