Bogota - The Colombian public prosecutor's office on Tuesday ordered the arrest of former senator Mario Uribe, cousin of Colombian President Alvaro Uribe, in the framework of an investigation over alleged ties with extreme-right paramilitaries.

The former senator, the leader of the party Democratic Colombia which backs the president, was linked to the case by the Supreme Court in October, and gave up his seat in the Senate so that the investigation could be derived to the public prosecutor's office.

The authorities said in a statement that the arrest warrant was preventive, and that it is not subject to bail.

The case known in Colombia as "parapolitics" involved some 60 legislators elected in 2006. Most of them belong to the centre-right coalition that backs President Uribe, and arrest warrants have been issued for 32 legislators.

More than 20 of the politicians involved have resigned their seats in Congress.

The case against the president's cousin is based mostly on the testimony of a former paramilitary who entered a witness protection programme and is now living in Canada. The witness claims Uribe's cousin seized land in the northern Colombian province of Sucre, with the support of the paramilitaries.

Mario Uribe is also said to have had commercial ties with former paramilitary boss Juan Carlos Sierra, currently charged with drug trafficking.

Over 31,000 members of the paramilitary United Self-Defence Groups of Colombia (AUC) demobilized from 2006.

When his cousin was first linked to the investigation, President Uribe said he was personally affected by the news, and admitted that he was "very sad." (dpa)