SINGAPORE - A 54-year-old man who sexually abused multiple children with learning or physical disabilities after offering to tutor them was sentenced to 45 years' jail on Monday (June 27).

The prison term handed down to the man - who lied to the victims' parents that he was a qualified educational therapist - is the longest imposed here for sexual offences.

In a case described by prosecutors as the "worst case of sexual offending against pre-pubescent children", the man admitted sexually abusing a total of eight victims over a period of 16 years, from 2002 to 2018.

He pleaded guilty to six charges of aggravated rape committed against three of the victims.

Two of the girls were five years old when they were raped, while the third was eight.

The man recorded videos of numerous attacks, which lasted for as long as 17 minutes.

Another 80 charges were taken into consideration during sentencing. They include various sexual offences committed against the seven girls and a boy when they were between the ages of five and 13.

The man cannot be named owing to a gag order, as he was in a relationship with the mother of one of the victims.

The offences came to light only after he sold his laptop in June 2018, and the buyer lodged a police report after finding obscene images in the device.

In sentencing, High Court judge Ang Cheng Hock said: "The exceptionally sickening sexual abuse perpetrated by the accused against multiple children of such a young age warrants a harsh sentence."

Justice Ang said the lengthy sentence was a strong message to like-minded offenders and reflected society's condemnation of the man's depraved acts against children who trusted him as a tutor and father figure.

The man will be 80 when he is released from prison, if he is given the usual one-third remission for good behaviour.

He told the court in Mandarin: "I'm very remorseful for the wrong I have done, it will haunt me for my entire life. I would like to sincerely apologise to the people I have hurt and I hope they can forgive me."

The court heard that the man volunteered as the chairman of a youth executive committee in 1998.

From 1998 to 2004, he taught cultural dance at a community centre.

His first victim – identified in court documents as V5 – got to know him through the dance activities.

The man knew her mother, who accepted his offer to tutor the girl.

Between 2002, when she was five, and 2004, he raped and tried to rape her on multiple occasions. The offences took place in toilet cubicles at Causeway Point, his Woodlands flat and a dance studio.

The man also got to know the mother of two victims - the boy, known as V8, and his younger sister, known as V4 - through the dance group.

In 2005, after the woman told him that her son had attention-deficit/hyperactivity disorder, the man lied that he had studied psychology and offered to tutor the boy.

He later also offered to tutor the boy’s younger sister, who had learning and hearing difficulties.

He tutored her behind closed doors and told her mother to sit in the living room so that she would not affect her daughter's learning.

In 2007, after the children’s father left the family, the man entered into a relationship with the woman and lived with her and the children.

Deputy Public Prosecutor Andre Ong said that unbeknownst to her, the man raped her daughter on four occasions in 2007 when she was between five and six years old.

The man eventually underwent a course from March 2007 to October 2012 for a diploma in learning disorders management and child psychology.

His relationship with the woman ended in 2015.

That year, he was introduced to the mother of a six-year-old girl, identified as V1, who had learning difficulties.

He claimed to be an educational therapist and gave the woman a name card bearing his name and supposed qualifications.

Between 2015 and 2018, the man gained the trust of V1’s family and was often invited to have meals with them.

The family did not know that under the guise of tutoring and providing speech therapy, he was taking obscene and naked photos of V1, molesting her, and ultimately raping her at his flat.

On June 3, 2018, a 40-year-old Filipina bought a laptop from the man.

Four days later, she clicked on a notification icon and a number of photos and videos depicting the sexual assaults were automatically imported from a cloud drive.

The man was arrested on June 11, 2018. He was later diagnosed to be a paedophile.

Trail of abuse over 16 years:

2002 to 2004: He raped V5 when she was five years old. Over the next two years, he raped and tried to rape her on another 15 occasions. He also forced her to engage in other sexual acts. He filmed most of the atrocities.

2002 to 2003: He rubbed himself against V6 on three occasions. She was seven to eight years old.

2004: He rubbed himself against V7 on four occasions. She was six to seven years old.

2006 to 2007: He took nude photos of V4 when she was five to six years old. He raped her on four occasions while filming the acts.

2009 to 2010: He recorded videos and took photos of V2 in the nude. She was 10 years old. He also stroked her body and rubbed himself against her.

2010: He took nude photos of V8 – the older brother of V4 – when the boy was 13 years old.

2014 to 2015: He took nude photos of V3 and rubbed himself against her on four occasions. She was seven to eight years old.

2016 to 2018: He took more than 200 obscene photos of V1. She was six to nine years old. He recorded his two failed attempts to rape her. He raped her on three occasions and filmed the acts. He rubbed himself against her on another four occasions.