A boy began sexually abusing his younger sister from when she was five and he was 12, continuing the assault for seven years and raping her repeatedly.

At times when she resisted, the boy punched her, slapped her and pinched her.

The offender, now 26, was sentenced in Singapore on Monday to 18 years’ jail and 24 strokes of the cane.

He pleaded guilty to two counts of aggravated sexual assault and one count of statutory rape, with another eight charges taken into consideration.

The offender cannot be named due to gag orders protecting the identity of his biological sister, who is now 19.

The siblings were close and lived with their parents and two older siblings in a one-room flat.