Biofuels such as biodiesel from soybeans can create up to four times more climate-warming emissions than standard diesel or petrol, according to an EU document released under freedom of information laws.

The European Union has set itself a goal of obtaining 10 per cent of its road fuels from renewable sources, mostly biofuels, by the end of this decade, but it is now worrying about the unintended environmental impacts.

Biodiesel from North American soybeans has an indirect carbon footprint of 339.9 kilograms of CO2 per gigajoule – four times higher than standard diesel – said the EU document, an annex that was controversially stripped from a report published in December.

It has now been made public after Reuters used freedom of information laws to gain a copy.

The EU’s executive European Commission said it had not doctored the report to hide the evidence, but only to allow deeper analysis before publishing.

“Given the divergence of views and the level of complexity of the issue … it was considered better to leave the contentious analysis out of the report,” the commission said in a statement.