The Waitomo fuel company says comments it made on Friday about an imminent price rise were about being transparent with customers - and not a marketing stunt.
On Friday independent fuel retailer Waitomo said they would have to increase the price from 6pm after their costs had gone up significantly.
It caused kilometre-long queues for petrol at many gas stations.
The Automobile Association said it may have been a marketing move, which worked.
AA spokesperson Terry Collins said New Zealanders were clearly on edge over fuel prices.
Whatever the motivation for Waitomo's comments, they sold a lot of fuel, he said.
"Well, everybody likes a bargain and that was a classic piece of marketing where they stated there was going to be a price increase and they set a cut-off time, and they managed to sell out all their product.
"They would say, hand on their heart, that they knew prices were going to go up and they let their customers know. Is that a marketing stunt? I don't know - but they sold every litre of their product."
But Waitomo insists the comments were not a stunt and were intended to be transparent with customers.
Petrol prices while high have stayed relatively stable since Friday.
Waitomo Group director Jimmy Ormsby said he wanted to be upfront with customers.
"In the context of being transparent to our customers, we said 'hey, our prices are increasing and we've got to pass this increase on', so it was no gimmick or self-promotion or anything like that - it's from my perspective, we were just communicating that our prices were going to go up."
Prices did go up - about 20 cents a litre for petrol, and 30 cents a litre for diesel, Ormsby said.