New World's impending shortage of SMEG knife blocks may soon land them in trouble with the Commerce Commission.

A customer has complained that the supermarket chain has breached the Fair Trading Act by failing to have enough blocks available to meet the demand.

New World owner Foodstuffs says the blocks were always advertised as being in limited supply, and they are confident they have met their legal responsibilities.

Jon Duffy, chief executive of Consumer New Zealand, told Heather du Plessis-Allan they may have done enough to breach the Act.

"Where it's not reasonable who you to believe that the stocks that you've got will meet the demand for selling goods at the price you've set or the promotion, and it could be that lower level that Foodstuffs has run foul of here."

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