The boss of Britain's biggest retailer Tesco (TSCO.L) on Friday hit back at critics, including the Bank of England, who have blamed supermarkets for stubbornly high inflation levels, saying the grocer was quick to react when commodity prices fell.
Some politicians and trade unions have raised concerns about profiteering by manufacturers and supermarkets.
But Murphy denied this was the case.
"We react pretty quickly when we see those commodities come down," he told reporters on Friday.
Earlier this week, Bank of England Governor Andrew Bailey commented on food price inflation, saying it had been slower to drop than global commodity prices.
Asked if he believed the Bank of England was being unfair in blaming the industry for high inflation, CEO Ken Murphy said: "Yes I do."
Food prices were made up of more than just commodity prices, Murphy said, adding that energy costs were also higher and labour costs were up, and he expected them to remain elevated given the shortage of workers in Britain.
Where commodity prices had come down - such as milk, bread, pasta and oil - the supermarket had cut prices, Murphy said. But he added that the price of some commodities had not fallen, such as potatoes and rice.
Britain's competition watchdog is examining grocery prices but has said that so far it has not seen evidence pointing to specific concerns.
Last week the French government secured a pledge from 75 top food companies to cut prices on hundreds of products.
While the British government has raised concerns about the surge in food prices it is not considering imposing price caps.
