SINGAPORE - A 24-year-old man who was roped in by another man to take part in a threesome with the latter's girlfriend without her knowledge and consent was sentenced to 17 years and 10 months' jail and 14 strokes of the cane for rape and other sexual offences on Friday (Aug 14).

High Court judge Pang Khang Chau found that Srihari Mahendran played a subordinate role in the trysts to the "real mastermind" - the woman's then boyfriend who had recruited him to fulfil his fantasy of watching another man have sex with his girlfriend.

Justice Pang said he could not ignore the leadership role played by the boyfriend, but noted that the boyfriend had pleaded guilty, while Srihari had contested his charges.

The 28-year-old boyfriend, a former auxiliary police officer, is serving a jail term of 19 years and 11 months for abetting Srihari to rape and sexually assault the victim on two separate occasions in 2016.

He was also sentenced to 24 strokes of the cane and cannot be named due to a gag order to protect the identity of his former girlfriend.

On Friday, Deputy Public Prosecutor Eunice Lau sought at least 19 years' jail and 18 strokes for Srihari, arguing that he played a pivotal role in the enactment of the boyfriend's deviant sexual fantasies.

She argued that Srihari derived pleasure from sexually assaulting the victim and had claimed trial despite overwhelming evidence that he took part in the planning process and the eventual offences.

Srihari's lawyer, Mr Ravinderpal Singh, argued that his client was just 20 years old at the time and is a first-time offender.

Although Srihari claimed trial, the victim did not have to take the stand to be cross-examined, Mr Singh argued.

He said Srihari should get a jail term of two-thirds of the sentence meted out to the boyfriend.

Srihari has engaged a new lawyer, Mr Edmond Pereira, who told the court that he will be filing an appeal against conviction.

Bail was increased from $60,000 to $100,000 and Srihari would have to wear an electronic tag pending appeal.

During the trial, the boyfriend testified that he wanted to have a threesome with his girlfriend and another man, but she rejected the idea.

He then hatched a plan to secretly bring another man into the hotel room to join their sexual trysts, while he watched and filmed the sex acts.

On April 29, 2016, the man let Srihari, whom he had met online, into a room at Hotel 81 Bugis while the victim was bound and blindfolded.

On Aug 7 that year, he again had Srihari join them at M Social Hotel in Robertson Quay. This time, she sensed something was wrong, took off her blindfold and saw a person leaving. Both men were later arrested at the hotel.

Srihari was found guilty of four counts of rape, one count of sexual assault by penetration, four counts of outrage of modesty, and one count of making an obscene film.

An 11th charge of transmitting obscene material was taken into consideration in sentencing.