Some food firms may be using inflation as an excuse to hike prices further than necessary, the chairman of Tesco has said.
Asked by Laura Kuenssberg of the BBC if food producers were taking advantage of the poorest in society, John Allan said it was "entirely possible".
He said Tesco was trying "very hard" to challenge price hikes it thinks are illegitimate.
Food costs including milk and cheese are rising at their fastest since 1977.
Mr Allan said all supermarkets were challenging cost increases from suppliers where they could - and Tesco was confronting companies it believed were increasing prices beyond what was necessary.
"We do try very hard to challenge (price hikes), I think," Mr Allan said.
Legitimate
"We have a team who can look at the composition of food, costs of commodities, and work out whether or not these cost increases are legitimate."
He said it was something Tesco's buying teams were dealing with "every day of the week".
Tesco, which has a 27.5% share of the Great Britain grocery market, had "fallen out" with"a number of suppliers after robust discussions over price hikes the supermarket had challenged, he said.
Most price hikes were legitimate, Mr Allan added.
"There have been some dramatic increases in commodity costs, energy costs and labour costs. On the other hand, if you don't want to pay £1.70 for soup in Tesco or any other supermarket, there are own-label alternatives," he said.
Heinz beans and tomato ketchup were among the products Tesco temporarily removed from shelves last year in a row over pricing. Kraft Heinz said at the time it was becoming more expensive to make its products.