The Government has no idea how long illegal building consents were being issued by Christchurch City Council or how many have been issued.
Last week International Accreditation New Zealand (IANZ) withdrew the council's ability to issue consents, because of concerns over technical processing that meant building consents might not meet the requirements of the building code.
On TVNZ's Q+A programme today, Building and Construction Minister Maurice Williamson said some external technical experts were brought in to try to evaluate the size of the problem.
He said the government did not even have a "ballpark" figure of the numbers of permits involved or for how long they were being issued.
"It might be that we go right back to the earthquakes," he said.