Mountain bikers from Whangārei are accused of being the "brainless idiots" who caused the deaths of three pregnant cows in Wānaka.
A local club for the sport has condemned the actions of the unaffiliated mountain bikers, saying it would be disappointing if they were confirmed to be Northlanders.
The Otago Daily Times reported the cyclists had ignored multiple signs about closed roads and stock movement at a remote Lake Hawea station last week.
Station farmers Nick Mead and Tim Lambeth were mustering a herd of 60 pregnant cows on a precarious stretch of Dingleburn Station Rd when the herd was spooked by the riders.
The riders, spooked themselves when they saw the mob, had dismounted their bikes and climbed up the bluff to get out of the way.