Cost increases from grocery suppliers to supermarkets continue to accelerate.

The Infometrics-Foodstuffs Grocery Supplier Cost Index shows an 8.7 percent rise last month.

Almost three times the number of products increased in cost than for the same month in 2019.

Infometrics Principal Economist Brad Olsen says farm expenses like fertiliser are rising at decade highs.

He says that means people who produce New Zealand tomatoes and the like are being hit hard with their own input cost increases.

Olsen says they're passing on those increases to the supermarkets,  and those are passed on to consumers.

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