The operating licence of an Auckland taxi company with a fleet of about 200 cabs has been revoked.
The New Zealand Transport Agency says it found the AA Yellow Cab company had seriously breached commercial transport laws which are intended to protect the public.
The agency's regional manager, Andy Thackwray, says it investigated the company twice after concerns about its ability to operate safely and legally.
The agency found that AA Yellow Cabs allowed an unlicenced driver to drive a taxi and failed to comply with log book and roster requirements.
Mr Thackwray says the company had been adequately warned and were unwilling or unable to fix the problems.
The company's licence has been cancelled, but individual drivers are still able to drive for other taxi firms, he says.