A Marlborough man has been jailed for two years following the slaughter of seals at a colony near Kaikoura last year.
Jason Trevor Godsiff, 19, was sentenced in the Blenheim District Court on Tuesday.
The court heard that he had been involved in clubbing 23 seals at Ohau Point.
The Department of Conservation (DoC) says two more dead seals were found later, and among the seals clubbed to death were 10 pups.
DoC says it is the heaviest penalty for animal cruelty it can recall. Its South Marlborough manager Dave Hayes says the sentence sends a clear message about animal cruelty.
"The judge made special mention of the scale around the incident, and of it being unprecedented. Since seals were protected we've not encountered such a large scale act of cruelty."
Co-accused Jemaal Large, 35, has not entered a plea and remains on remand.
Mr Hayes says the Kaikoura seal colony has recovered well since the killings.