Mario Uribe has been a close political ally of President Uribe
A cousin of Colombian President Alvaro Uribe has been rearrested over his alleged ties to paramilitary groups.
Mario Uribe Escobar, a former senator, was detained following an order from the Colombian Supreme Court.
Mario Uribe, who denies any wrongdoing, was detained for several months in 2008 but subsequently released for lack of evidence linking him to paramilitaries.
Dozens of current and former lawmakers have been jailed or investigated over their alleged links to paramilitaries.
Former paramilitary leaders have alleged that Mario Uribe conspired with their groups in the 1990s to take over farmland in agriculturally rich regions of Colombia that were under paramilitary control.
The right-wing militias were created by landowners and drug traffickers to combat left-wing rebels and anyone suspected of being a sympathiser.
Mario Uribe, a close political ally of President Uribe, is one of the most prominent figures arrested over alleged paramilitary links.
The case has recently been reopened by the Supreme Court.
Many current or former members of congress have been jailed or investigated for allegedly conspiring or collaborating with United Self-Defence Forces of Colombia (AUC) paramilitaries, in what has been dubbed the "parapolitics" scandal.
Many of those investigated are allies of President Uribe. The president remains popular, however, for pursuing aggressive military action against leftist rebels.
He also negotiated the 2003 peace deal that saw paramilitary leaders surrender and demobilise 31,000 of their men in exchange for reduced jail terms and protection from extradition.