TWO prisoners, defending themselves against allegations of torturing their former cellmate and forcing him to perform sexual acts, on Tuesday took turns to grill their accuser from the dock.

The first, Iryan Abdul Karim, 21, had a bundle of documents in his hands as he continued his questioning, which began on Monday afternoon, to challenge the alleged victim's version of events.

The second, Muhammad Hamdan Abdul Rahman, 20, launched his cross-examination with a speech accusing the victim of telling lies to seek revenge.

The two - together with Mohammed Zameen Abdul Manoff, 21 - are facing multiple charges of physically and sexually assaulting the 22-year-old in their Changi Prison cell between April 27 and May 4 last year. The alleged victim, who cannot be named under a court order, was hospitalised for two months.

The trio admit beating up their former cellmate. But they dispute parts of his account and maintain that he was a willing party in the acts of oral sex.

'I'm not claiming innocence, neither am I guilty of all the charges that you are accusing me of,' said Hamdan in English on Tuesday as he accused the victim of exaggerating and fabricating statements.

But the accuser stuck to his account. On Monday, he had testified that his cellmates had beaten him up to 'punish' him for bragging. When he could not take the beatings, he voluntarily performed oral sex on them to get them to stop.

Also speaking in English, Iryan posed his questions calmly as he took the victim through his testimony. For instance, he questioned his account that he had suffered a swollen eye and bruises. Given that they were subject to strip searches, how did these injuries escape detection by prison officers?

The accuser said that he would avoid direct eye contact with the officers, and that his dark complexion hid the injuries.

Iryan also disputed the victim's testimony that he was forced to choose from a blind list of 10 punishments which included sodomy and oral sex. Iryan said he wrote the options himself and they did not contain sex acts.

Read the full story in Wednesday's edition of The Straits Times.