"In the good old days, a homologation number was assigned to anyone wanting to import seats and, if that wasn't evident on the paperwork, Customs wouldn't release them. Some years ago government funding was reduced and this process has been eliminated," he said.
He said "substandard manufacturers" were making very low-quality seats. "These seats have clearly never been tested to the displayed labelling and often these will have more than one label on them."
Auckland father Matt Hancock said he bought his children's car seats from overseas because he found the seats available in New Zealand were not suitable.
"In my opinion we have very lax laws and standards in New Zealand. My wife is American and, when we were looking for car seats, we did heaps of research and found the seats overseas were 100 per cent better than what we came by here," he said.
He wanted his children to use Isofix or Latch seats which he said were easier to install.
Plunket child safety adviser Sue Campbell said New Zealand's car seats were as safe as those available elsewhere but the problem was New Zealand had more than one standard. She said parents could use car seats under the New Zealand, Australian, European or US standards.
"We have been calling for one clear standard for New Zealand for some time now. It is confusing for parents because New Zealand allows seats under more than one standard and there are quite a variety of seats available.
"For a car seat to perform correctly in an accident, it needs to be installed correctly." she said.
For information on car-seat rental schemes near you, visit www.plunket.org.nz