A jail extension - for a former Dilworth housemaster and scouting volunteer serving time for historic sexual abuse of five students

Nearly two years have been stacked on top of Ian Robert Wilson's three years and seven months, after admitting the abuse of five more boys.

The 71-year-old was first arrested in 2020, for historical abuse at the Auckland boys' boarding school -- where he worked for 25 years, until 1996.

Judge Belinda Sellars called his offending abhorrent.

She says the extra years equate to the sentence Wilson would've faced if he'd been sentenced for all 10 victims at once.