I smuggled tons of cocaine, Colombia warlord tells U.S. court

Diego Murillo, formerly a top commander in the right-wing paramilitary United Self-Defence Forces of Colombia, pleaded guilty to conspiring to smuggle tons of cocaine into the United States.

Murillo, 47, acknowledged through an interpreter that he conspired with 'military, political and anti-communist' forces to distribute cocaine there.

Confession: Murillo, pictured on arrival in the U.S. last month, says he conspired with others to distribute cocaine there

As a condition of Murillo's extradition to the U.S. last month, prosecutors agreed only to call for him to serve between 27 and 33 years in prison, rather than life.

Murillo's lawyer, Paul Nalven, did not say why his client had pleaded guilty, but noted that the sentence 'could have been a lot worse' had he been convicted at trial.

Other drug kingpins from Colombia have recently been sentenced to terms as long as 45 years.

The warlord was one of 14 paramilitary leaders taken from Colombian jails and extradited to the United States last month to face drug charges.

Human rights groups expressed fears that the plea deal would thwart attempts to hold Murillo to account for hundreds of murders in Colombia.

Some of the killings are said to have been carried out while he was a top leader of the paramilitary AUC, and some during his long career in organised crime.

Ivan Cepeda, director of the Movement of Victims of State Crimes, an activist group in Colombia, said he hoped the plea bargain wouldn't end efforts to persuade Murillo to provide information about 'forced disappearances' and other atrocities committed during the country's long civil war.

'I'm worried that these agreements are going to leave out any possibility of solving crimes against humanity,' he said.

Mr Nalven said arrangements would be made for special prosecutors from Colombia to interview Murillo in the U.S. about the human rights allegations.

Murillo will be sentenced in December.