Motoring experts say the Transport Agency's failed to protect people from dodgy Warrants of Fitness.

A review of shady vehicle inspectors has shown about 10,000 vehicles will need to be re-checked, with possibly more to come.

Autotalk.co.nz editor Richard Edwards told Mike Hosking people should be able to have faith in the system.

"There will be people out there who know I can go and get a warrant on this car that's a bit dodgy there, but there are also that person who is also just down the road and that might be their closest workshop. They are arguably the innocent victim."

"These are a large number of cars that potentially haven't been correctly checked. Now I am not saying those are necessarily unsafe cars but it's concerning that the system has collapsed in such a way that this has happened." 

He said while there has been one fatality identified as being potentially from a dodgy warrant, the likelihood of every car being dangerous is slim.

"I don't think, by and large, every car in that 10,000 is going to be critically unsafe."

Edwards said the NZTA's system to check their own staff has failed.

"We have a fairly good system for inspecting vehicles. What we are seeing here is the NZTA's internal system for actually putting the checks and balances in place for those people within the system has failed, it appears to be incredibly lacking over the last five or six years."

"There has been some kind of failure of structure, some kind of failure of resource, these things just haven't been checked right."