A former senator with close political ties to President Alvaro Uribe was arrested by Colombian authorities Wednesday on charges of colluding with far-right death squads. Mario Uribe, a second cousin to the president, is one of the most prominent figures in a scandal that has sent dozens of current or former lawmakers to jail on charges of benefiting from links to outlawed rightist paramilitary groups. Under an order handed down by Colombia's Supreme Court, Uribe was arrested in the city of Medellin, 155 miles (250 kilometers) north of Bogota, police said. He was to be transferred to the capital. The 60-year-old former senator has denied any wrongdoing. Uribe, who presided over the Senate in 2000-2001, is a close confidant of Colombia's conservative president. The two launched a political party together in the mid-1980s and have remained allies ever since. The arrest stems from allegations by a former paramilitary leader that Uribe conspired with right-wing militias in the 1990s to gain control of land in northeastern Colombia's agriculturally rich regions where paramilitaries controlled large swaths of territory. The former paramilitary leader, Jairo Castillo, alias 'Pitirri,' claims he witnessed a meeting during which Uribe negotiated a deal with paramilitary leaders to obtain prime cropland. Paramilitary groups formed in the 1980s to defend wealthy ranchers from kidnapping and extortion by Colombia's leftist rebels, but evolved into drug-trafficking criminal mafias. Prosecutors blame them for at least 10,000 murders and the theft of millions of acres of land. Uribe was imprisoned for four months in 2008 on charges of colluding with paramilitaries, but he was released in August of the same year after Colombia's No. 2 prosecutor said there was insufficient evidence to hold him. He remained under investigation, however, and was barred from leaving the country. 