Colombia's government proudly claims that it is the biggest producer of biodiesel and ethanol in Latin America after Brazil, but human rights groups do not share that enthusiasm.
Critics warn that the cultivation of palm trees to produce biodiesel is a threat to Colombia's indigenous groups and other minorities, including Afro-Colombians.
In rural areas, there is evidence that some people have been forcibly displaced to make way for biofuel production.
Last year, the United Nations stopped its investment in the sector in Colombia.
But while ethanol production in Brazil has been pored over by experts and activists, the challenges faced by Colombia remain relatively unexamined.
Colombia's agriculture minister, Andres Fernandez, stresses that one of the main aims of President Alvaro Uribe's administration is to keep the production of biofuels "on a growing path".
Mr Fernandez argues that this is "not one government's policy, but State policy".
He dismisses accusations that the production of biofuels squeezes food output.
"There are 4.5 million hectares of cultivated land and another 4.5 million of hectares of uncultivated land, [but] that land would not be used for food production - it would stay just as it is," he says.
Fuel or food?
Last year, UN food chiefs warned that governments had to review urgently their policies on growing crops for biofuels.
The UN Food and Agriculture Organisation (FAO) said biofuels were of "limited use" for solving the planet's energy needs.
At the same time, they pushed up food prices by diverting valuable crops such as sugar maize and oilseed from food use to energy use.
 Families and children from Choco have been forced off their land |
Mr Fernandez says he respects the UN viewpoint and its decision to suspend investment in biofuels in Colombia, but he says his country has its own perspective.
He argues that bio-fuels have had a "wonderful effect" and have led to investment in deprived areas of the country benefiting peasants and minority groups.
But this effect is not viewed quite as wonderfully by many rural workers in the Choco province, in north-west Colombia.
They complain of being forced off their land to make way for palm trees - and accuse the government of being deaf to their pleas for help.
One of the workers, Eustaquio Polo Rivera, told BBC Mundo that he lost his land after an incursion by right-wing paramilitaries in 1996.
"We used to produce what we needed for ourselves: bananas, corn, rice. But one day, soldiers just arrived and took our land. They destroyed everything in the community," he says.
"They told me they needed the land to fight the guerrillas, but we soon realized that the point was to take our land.
"We tried to resist, but the armed men warned us they would take no responsibility for the families who decided to stay."
Violations denounced
According to Mr Polo, more than 500 people fled immediately.
"When we tried to go back, our land was planted with palm trees," he says.
"In my own community, there are between 30 and 40 hectares of palm trees.
"The government hasn't shown any interest in returning our land because the paramilitaries carry on moving from one location to another and the big companies have powerful allies."
Fidel Mingorance is chairman of Human Rights Everywhere (HRE), one of several NGOs denouncing the forced displacement of communities, often of African descent, to make way for palm trees.
"It all started in Tumaco, in South Colombia, and now there are all sorts of violations - forced displacement, assassinations, property invasion," he says.
Leonidas Tobon, the director of technological development at the Ministry of Agriculture, accepts there was a case of forced displacement in Choco, but says it was a one-off.
"The cultivation of palm trees is concentrated in four regions. Only 10% of it is in areas occupied by Afro-Colombians and 30% of land used to grow the trees belongs to small farmers in any case," he says.
