SINGAPORE - He was only 13 years old, and she was nine, but that did not stop him from sexually abusing his cousin over three years from 2014.

It only ended when the victim feared that she may be pregnant and her teacher was alerted.

The offender, now 20, was sentenced on Thursday (Oct 29) to at least a year's reformative training.

He will be detained at a centre and made to follow a strict regimen that includes foot drills and counselling. The youth cannot be named to due to a gag order to protect his cousin's identity.

He was waiting to enlist in national service when he pleaded guilty earlier this year to two counts of sexually penetrating a minor and a molestation charge.

Fourteen other similar charges involving the girl, who is now 15, were considered during sentencing.

Deputy Public Prosecutor Chong Kee En told the court that the cousins were close and played together as children. He would sometimes also help the girl with her schoolwork.

The pair were in a flat in early 2014 when the girl walked out of a bathroom naked.

The DPP said: "Although he was not aroused initially, the desire to see the victim naked again began to fester in his mind."

Later that year, the girl was lying down on their grandmother's bed when he felt an urge to touch her.

He asked her if he could do so and when she nodded her head, he undressed the girl and molested her.

The court heard that the youth was disgusted with himself after doing it. But he also decided the consequences were "not as bad", as he felt the victim probably could not understand what had happened.

About six months later, he molested her again and by December 2014, the acts of abuse were more serious with him sexually penetrating her without a condom.

He then sexually abused her multiple times from 2015 to 2017.

The DPP said that the girl started feeling a pain in her stomach on Aug 15, 2017.

He added: "Although the accused did not penetrate her vaginally - but anally and orally - she thought pregnancy could occur from anal penetration."

She told her close friends that she was afraid she might be pregnant. She also said her cousin had sexually abused her.

The girl's teacher later found out about the offences and the police were alerted.

DPP Chong said: "During all of the sexual activities, the victim felt scared, uncomfortable and confused as to why the accused was doing these acts.

"Although she felt uneasy about it, she did not really understand the seriousness of the matter. She also kept quiet about all the previous incidences as she did not want her family to break up."

The girl later went for a medical test and was found to be free from sexually transmitted infections. The offender has since apologised to her parents, the court heard.

He was offered bail on Thursday and ordered to surrender himself at the State Courts on Nov 12 to begin serving his sentence.

For each count of sexually penetrating a child below 14 years old, an offender can be jailed for up to 20 years and fined or caned.