An urgent review has been called after the NZ Transport Agency failed in its duty to properly monitor companies that certify vehicle safety.
Independent lawyers have been called to conduct a review of 850 open compliance files after the NZTA did not meet its regulatory responsibilities.
- NZTA defends Auckland cyclists slammed for riding side by side
- NZTA 'disappointed' excavated Kauri tree isn't a waka
NZTA regulates all vehicles on the roads and licences people working in the transport sector.
Phil Twyford said NZTA was failing in its duty to properly check the companies that certify vehicles as safe for the road, and other services.
"When problems with these companies were identified, there was often no follow up," he said.
"This is very disappointing. Public safety must be paramount.
"There has been a regulatory lapse.
"This failure, in my view, was in part a result of a reduced focus on the Agency's regulatory role over the last decade.
"Staff were redeployed and there was an emphasis on education rather than enforcement."
He said certifications will be revoked where necessary or other actions taken on a case by case basis.
"The Board will look into how this went on for so many years and why it was not dealt with earlier.
"The Board has also advised me that the Transport Agency will be taking a more rigorous and pro-active approach to safety regulation from now on."
NZ Transport Agency Chief Executive Fergus Gammie says it is clear that major improvements are needed.
"It is clear that our approach has not been sufficiently robust to categorically ensure the highest levels of regulatory compliance."
Around 152 of the 850 cases have been prioritised around risk to safety.
The review of these files, further investigations and actions are expected to be complete by early November.