The US-financed anti-drug programme is the world's largest
A Colombian judge has ruled that the authorities may resume spraying pesticides to destroy illegal drugs on land belonging to indigenous Indians.
In an earlier ruling, circuit judge Gilberto Reyes had said that chemicals used in the US drug eradication programme violated the right to life and the environment of those on Indian reserves.
The spraying of drug crops in Colombia - both coca and poppy, the raw materials for cocaine and heroin - is the centrepiece of the US war against drugs in the region.
Colombia produces more than 80% of the world's cocaine, and is the single largest supplier of heroin to the US.
Opposition to the fumigation has been growing in Colombia along with the scale of the spraying - more than 50,000 hectares so far this year alone.
Opponents insist that the spraying of the glyphosate weed killer is harming people and the environment.
US pressure
Their call for a suspension to the fumigation has been echoed by the United Nations and the World Health Organisation.
But the US threatened to cut off aid if the fumigation programme was halted.
Through its ambassador to Colombia, Anne Patterson, huge pressure was placed on the Colombian Government to get the decision reversed.
Senator Rafael Orduz, a leading opponent of the fumigation, lamented the decision.
He said that spraying over the last decade had achieved nothing, and that more drug crops than ever were under cultivation - an assertion supported by US figures.
Mr Orduz insists that the Colombian peasants who grow the drug crops - most of whom live in poverty - should be offered real alternatives.
He also says the US should do something about its demand for drugs before pouring weed killer on Colombia.
According to the US Drug Enforcement Agency, the demand for illegal drugs in the United States last year totalled over $60bn.