Instead, Statistics NZ had been given extra funding to expand the sample size to 20,000 households, rather than just 6000.
As the survey was currently being carried out, that information won't be available until mid next year.
But even without the Ministry's information, Becroft said he could tell there had been little change in the past two years.
"The other indicators we usually follow have shown little sign of either a significant increase or decrease in recent years."
The number of children - about 80,000 - currently experiencing material hardship in New Zealand could fill Eden Park twice, he said.
He was buoyed that a new bill - the Child Poverty Reduction Bill - was about to pass its third reading in parliament, an effort he praises both National and Labour for both supporting.
"That was a game changer ... having a cross-party accord is historic and the bill is about to be passed any day now and it will be all systems go and I will be watching very closely."
He said a key way to tackle child poverty would be to see benefits - which go to parents with children - increased annually, rather than the current sporadic nature of when a Government sees fit.
"The evidence is, the increase in benefits invariably go to children. I mean the stereotypical put down is that more money into the hands of families invariably means more on alcohol or gambling or cigarettes. But no, the evidence is that it usually is spent by parents who really are concerned about their children."
Becroft said overall he was "optimistic" about changing the statistics.
"I'm deeply concerned about the situation currently. It hasn't got worse but we could do much better and I'm pretty sure we will."