SINGAPORE - A young man restrained a then 13-year-old girl while his friend raped her.

Tan Wei Guang, now 20, was sentenced to reformative training on Tuesday (Aug 29) for abetting Alson Tan Yu Seng in committing the offence.

Tan Wei Guang, who pleaded guilty to the offence in June, befriended the girl through Facebook in 2013.

She later told the youth that she liked him, the court heard.

In December 2013, he met Alson Tan and Bryan Ong Jing Chong, both 18 now, for a game of basketball near Alson Tan's flat in Senja Road.

The girl subsequently joined the trio at the basketball court that evening before all of them went to the ground-floor unit to rest.

They were hanging out in Alson Tan's room before the three youths decided to step out to smoke, leaving the girl alone inside.

While in the living room, Alson Tan revealed to his friends that he had seen the headman of his gang, Koh Rong Guang, raping the girl.

Deputy Public Prosecutor Stella Tan said: "Alson then suggested to Bryan and the accused that they could have sex with the victim. The accused and Bryan agreed to his suggestion and played scissors-paper-stone to determine the sequence of who was to have sex with her."

The trio then returned to the bedroom and Ong pulled her off the lower bunk of a double-decker bed where she had been resting.

DPP Tan said Tan Wei Guang and Ong then held the struggling girl down, pinning her arms against a mattress while Alson Tan penetrated her without a condom.

They stopped only when they heard Tan Wei Guang's brother knocking on the bedroom window. They released the girl and left to meet him outside.

The girl left the flat and made a police report on July 5, 2014.

Tan Wei Guang's lawyer, Mr Gino Hardial Singh, told District Judge Eddy Tham on Tuesday that his client wanted to defer his sentence by two weeks to spend more time with his newborn son.

He is now out on bail of $20,000 and will surrender to the court on Sept 12.

Both Alson Tan and Ong have already been dealt with in court and were also sentenced to reformative training earlier this year.

The case involving Koh, now 24, is still pending.

Offenders sentenced to reformative training have to spend between 18 months and three years in a reformative training centre.

They must follow a strict regimen that includes foot drills and counselling.

For abetting rape, Tan Wei Guang could have been jailed for between eight and 20 years, with at least 12 strokes of the cane.