Palm oil is one of the biofuel crops stirring controversy
The replacement of traditional fuels with biofuels has dragged more than 30 million people worldwide into poverty, an aid agency report says.
Oxfam says so-called green policies in developed countries are contributing to the world's soaring food prices, which hit the poor hardest.
The group also says biofuels will do nothing to combat climate change.
Its report urges the EU to scrap a target of making 10% of all transport run on renewable resources by 2020.
Oxfam estimates the EU's target could multiply carbon emissions 70-fold by 2020 by changing the use of land.
The report's author, Oxfam's biofuel policy adviser Rob Bailey, criticised rich countries for using subsidies and tax breaks to encourage the use of food crops for alternative sources of energy like ethanol.
"If the fuel value for a crop exceeds its food value, then it will be used for fuel instead," he said.
"Rich countries... are making climate change worse, not better, they are stealing crops and land away from food production, and they are destroying millions of livelihoods in the process."
Opportunity - or crime?
Biofuels are a divisive issue with strong arguments on both sides.
Leaders such as Brazilian President Luiz Inacio Lula da Silva have suggested the biofuel boom provides developing nations with a great opportunity.
He says it creates a profitable export for energy crop producers in Africa, Central America and the Caribbean that could enable them to claw their way out of poverty.
But several aid agencies and analysts have warned of the possible downside of biofuel crop cultivation.
One UN adviser went as far as describing biofuels as a "crime against humanity".