BOGOTA, June 18 (Reuters) - The office of Colombia's Attorney General has opened an investigation into former President Alvaro Uribe for crimes linked to the creation of a paramilitary group, two massacres and the murder of a human rights defender, according to a source and a post from Uribe on social media on Thursday.
Uribe, 73, served as Colombia's president for two consecutive terms between 2002 and 2010.
Uribe was convicted last year for fraud and bribery in a lengthy legal saga over alleged witness tampering that could have resulted in him serving 12 years of house arrest. The decision was overturned on appeal, but is now under review by the country's top court.
Leftist senator Ivan Cepeda, who is running in Sunday's presidential run-off, is classed as a victim in the witness tampering case.
Uribe was Colombia's first-ever former president to be criminally convicted, though he always maintained his innocence, calling the case a political persecution.
The case revolved around allegations he ordered a lawyer to bribe jailed paramilitaries to discredit claims he had ties to their organizations.
The paramilitaries, funded by cattle ranchers, landowners and merchants to protect themselves from leftist guerrillas, are estimated by a truth commission to be responsible for nearly half of more than 450,000 people killed in Colombia's conflict between 1985 and 2018.
Last year, Uribe's brother was convicted for crimes linked to the paramilitaries and sentenced to 25 years.
A source from the attorney general's office told Reuters Uribe had been summoned for questioning in the new investigation and the date has yet to be decided.
"This is a clear case of political pressure and injustice," Uribe said, alleging ties between Cepeda and the prosecutor who summoned him and saying his lawyers named four well-known sites of paramilitary massacres and violence about which he will face questioning.
Colombians are set to go to the polls on Sunday to elect their next president in a runoff vote that will pit Cepeda against right-wing lawyer Abelardo De La Espriella, who has Uribe's backing and has vowed a tough approach to rebel groups.
(Reporting by Luis Jaime Acosta in Bogota; Writing by Andre Romani; Editing by Sarah Morland and Julia Symmes Cobb)
