General Motors boss Rick Wagoner has dismissed United Nations research that links biofuel production to rising food prices as 'shockingly misinformed'.
His blunt assessment follows intense debate about the social costs and environmental benefits of biofuels, a growing industry that some analysts say has a negative impact on food production.
The UN's Food and Agricultural Organisation has linked biofuels production, along with factors such as crop failures and the falling dollar, to the rise in world food prices.
However, Wagoner said: 'Oil prices are a far bigger driver of higher food prices than ethanol.'
GM produces about a million flex-fuel vehicles that can use biofuel in the US each year, while its Saab brand is a leading proponent of biofuels in Europe.
The European Union, meanwhile, is set to re-evaluate plans to use up to 10% biofuels in all transport fuels, as a result of concerns about its impact on the environment.