"For this reason, we strongly encourage people who have a current Warrant of Fitness from Westland Mechanical and Tyre Limited to get their vehicle rechecked.
But Zakeri denied there were any problems.
"I haven't done anything wrong. Just leave me alone please," he told the Herald politely on the phone this morning.
The agency said it would contact all 3721 affected vehicle owners as soon as possible to advise them of recheck options.
It follows a case last week in which a Northland garage had its licence to issue warrants of fitness suspended indefinitely after it issued a WoF to a vehicle which was later involved in a fatal crash.
New Zealand Transport Agency chief executive Fergus Gammie said the circumstances which saw Dargaville Diesel Specialists issue a WoF to an "unsafe" car which was involved in a fatal crash on January 6 this year were "totally unacceptable".
Sixty-five year-old William Ball was a front seat passenger in a car which lost control and crashed into a ditch on State Highway 12 near Turiwiri, Dargaville. He died 26 days after the crash.
The driver of the vehicle has pleaded guilty to driving-related charges but has yet to be sentenced.
Police investigating the crash found the front seat passenger seatbelt was frayed and failed in the crash.
NZTA said Dargaville Diesel Specialists (DDS), who had issued a WoF to the car in December 2017, admitted it had done so without properly inspecting the vehicle, in particular, the seatbelts.
"Dargaville Diesel Specialists didn't check the vehicle properly. They failed William Ball," Gammie said.
"However, the NZ Transport Agency's regulatory regime also failed him and that is unacceptable."
The NZ Transport Agency was aware DDS had serious regulatory compliance issues on an intermittent basis since 2011.
There were a number of opportunities to undertake enforcement action, and the most serious infraction took place just weeks prior to the crash when NZTA observed staff issuing warrants without properly inspecting vehicles, including seatbelts.
In late August, DDS was suspended from issuing any vehicle certifications.
DDS owner Rodney Wilson disputed that he had a shoddy inspection system.
He said he had been involved in mechanics for 50 years and there was no way he would do anything that impacted on people's safety.
''I've had 50 years in the mechanics trade and they are telling me that I don't know anything about cars and safety. It's bullshit,'' Wilson said.
''The whole WOF system is crook and needs fixing. The whole system is wrong.''
He said the seatbelt on the vehicle involved in the fatal crash was not in the condition it was at during the crash when he tested it.
''There's no way I would let that car pass the warrant if the seatbelt had been like that when I tested it. No way.''
NZTA has written to all vehicle owners receiving WoFs from DDS to strongly recommend they get their vehicles re-checked, with NZTA meeting the cost of re-inspection.
