By Jeremy McDermott
BBC News, Colombia
Murillo was sentenced to 31 years in an American jail
A drug lord imprisoned in US has said that he and his illegal paramilitary army funded the 2002 election campaign of Colombian President Alvaro Uribe.
Diego Murillo, aka Don Berna, was one of the heads of the AUC, which demobilised after a peace settlement.
He was extradited to the US by the president in 2007, and imprisoned by a New York court for drug trafficking.
A denial has been issued by Fabio Echeverry, who managed President Uribe's campaign finances in 2001.
After being sentenced on Wednesday, Don Berna appears to have decided he has nothing to lose and stated through his lawyer that he had contributed large sums of money to the campaign of Mr Uribe in 2002, when he was running for president.
Don Berna was the successor of drug lord Pablo Escobar in the city of Medellin.
He then joined the brutal AUC, or the United Self-Defence Forces of Colombia, as it fought, often in cahoots with the military, to destroy the Marxist rebels.
The AUC was a 30,000-strong illegal right-wing paramilitary army.
The accusation against Mr Uribe is a very serious one and has generated widespread reaction here in Colombia.
Ever since Mr Uribe started his political career, he has been dogged by accusations of links with right-wing paramilitaries.
During his term as governor of the province of Antioquia the AUC was born, flourished and spread across the country, leading to the deaths of more than 100,000 Colombians.
Currently there are 77 congressmen under investigation for links to the AUC, nine of whom have been condemned.
Almost all are supporters of President Uribe.
Despite the denial, the scandal is unlikely to die quietly as Don Berna has not yet finished delivering his revelations.