Four Western Bay dairy farmers have broken employment laws in recent years, according to workplace watchdogs.
A trade union leader is citing the breaches as evidence the farming sector is "out of control" and needs to be more accountable.
Information released to the Bay of Plenty Times under the Official Information Act showed labour inspectors began investigations at nine Western Bay of Plenty farms between July 2012 and February this year and found four had breached at least one employment law.
One dairy farm resulted in the Ministry of Business, Innovation and Employment labour inspectors taking enforcement action. The inspectors achieved compliance during or after their visits to the other three farms.
Federated Farmers Bay of Plenty president Rick Powdrell expected ignorance was the cause of most breaches.