The Government's move to cap wheel clamping fines at $100 was based on anecdotal evidence, media reports, and a lack of overall evidence about the scale of the problem, according to the Ministry of Business, Innovation and Employment (MBIE).
And MBIE was "not satisfied" that there is enough of a problem to warrant Government intervention.
"While there is anecdotal evidence of problems with wheel clamping, we are not satisfied that there is a convincing case for a particular change at this point in time," the MBIE regulatory impact statement said.
The Government announced its intention to bring in the $100 cap in August last year, and legislation to introduce the cap is expected to have its first reading in Parliament this week.
MBIE recommended a $50 cap, but the Government decided to increase this after concerns that a low cap could put some wheel clamp operators out of business.
A low cap was also seen as an ineffective deterrent that could see business carparks occupied by people other than legitimate customers.
The MBIE statement said it was based on anecdotal evidence, including media reports, and meant that MBIE was unable to assess the scale of the problem.
But it noted several issues in the industry. Unclear regulation had led to unreasonable fees, intimidating and unfair behaviour by wheel clamp operators, and a lack of opportunity for appeal before paying the release fee.
"There is nothing in the law that prohibits, for example, the clamping of vehicles thirty seconds after the motorist has vacated.
It noted one instance where someone paid $760 after parking for half an hour, and another of a $480 payment to release a clamp after parking for five minutes.