Former President Alvaro Uribe said here Friday that the criminal investigation launched against him in Colombia's Supreme Court for alleged witness tampering has been influenced by incumbent head of state Juan Manuel Santos.

"I am very concerned about what is being rumored in this Court regarding pressure in the investigation from the president of the Republic," Uribe said at a press conference in Bogota.

Uribe governed Colombia from 2002-2010, when he was succeeded by Santos, his erstwhile defense minister.

The rightist former president filed a motion on Friday asking the Supreme Court to close the investigation launched against him for alleged witness tampering in a case involving leftist Sen. Ivan Cepeda.

That case dates back to 2012, when Uribe accused Cepeda of suborning witnesses to testify against him.

Cepeda was said to have convinced jailed right-wing paramilitaries to link Uribe to the militias in his native province of Antioquia, where the future president served as governor in the 1990s.

Last Saturday, however, the Supreme Court released a 219-page document in which Justice Jose Barcelo Camacho proclaimed Cepeda's innocence.

The finding was doubly adverse for Uribe, as Barcelo also ordered an investigation into the former president for witness tampering and perpetrating a fraud on the court.

Uribe's Centro Democratico party calls the investigation part of a plot to damage its prospects in the March 11 legislative elections, in which the former president is running for the Senate.