"The member of the public who alerted us at the outset did exactly the right thing by phoning 0800 POACHING (762244)," he added.
Those who set out to poach spawning trout are liable for prosecution with penalties of up to two years' jail. "All reports made to Fish & Game are investigated, and we are grateful to vigilant members of the public who alert us to suspicious behaviour," he added.
"We extend our thanks to the police too for turning out so quickly. Poaching on such as scale if unchecked is a drain on the Rotorua economy in the damage it can cause to fish stocks.
"Sports fishing, that's worth many millions in local income, depends on our ability to protect spawning and maintain a healthy fishery."
Fish & Game officers seized a gill net at the scene of last Friday's incident and are continuing to investigate, with a number of charges being considered.