The country's largest supermarket group says it's losing money on some butter sales

Stats NZ data analysed by Newstalk ZB shows an average 500-gram block of salted butter is almost double the price of early last year - -- now eight-dollars 59.

Some stores are selling it below the average.

But Foodstuffs North Island Managing Director Chris Quin says in some cases, they are selling it at a loss.

He says they choose to invest in core butter products like Pams, to make the price as affordable as possible.