A rope-skipping coach was yesterday found guilty of sexual offences against a student who was a minor.

While the judge found the victim's testimony to be believable and credible to some extent, he found it not sufficient to convict Roger Yue Jr, 59.

Instead, it was Yue's own words that did him in.

What sealed his fate was a statement he had given to the police, as well as an interview with a psychiatrist. These revealed that Yue considered himself to be in a relationship with the girl and that he performed various acts on her, including using objects to sexually violate her.

The offences took place between 2008 and 2010 when the girl was between 13 and 14 years old.

The victim, who is now 22, cannot be named because of a gag order to protect her identity.

She got to know Yue in 2006 when he was appointed to coach her primary school's rope-skipping team.

He later invited the girl to join a private competitive rope-skipping team and got her to help him as he coached teams from several schools.

The victim said Yue sexually abused her until late 2010. Eventually, she told her polytechnic lecturer and counsellor about her ordeal. She made a police report on April 28, 2014.

Delivering his decision yesterday, Justice Aedit Abdullah said the fact that the victim did not tell anyone in authority about the incidents until about five years later "gave some pause".

The victim's behaviour in continuing with training and maintaining contact with Yue may also seem odd, given that she was being sexually abused repeatedly.

But the High Court judge accepted that victims of sexual abuse may not behave in a stereotypical way.

The judge said that while early reporting gives strong support to the case against an accused, a delayed report did not necessarily suffer from reduced credibility, although it may make it more difficult to prove a case beyond reasonable doubt.

The judge added that a juvenile cannot be expected to always react in the same way as an average adult, that is, to report an assault as soon as possible.

"The thinking process, assumptions and viewpoint of a juvenile victim may lead to a course of action that may appear unreasonable or improbable," said the judge.

Yue was convicted of two counts of statutory rape and five counts of sexual penetration of a minor after the court accepted the victim's evidence that the sexual acts were committed through "what was at least cajoling, if not pressure" by the accused.

Yue, who is out on bail of $70,000, is expected to return to court on March 21 for sentencing arguments.