Bogota, Colombia (CNN) -- Former Colombian President Alvaro Uribe denied accusations Thursday that he ordered the government's spy agency to wiretap his political opponents.
"I never gave orders to do anything illegal," Uribe said during the day's session of a congressional inquiry, arguing that there was a "criminal conspiracy" against him fueled by his political enemies.
Critics allege that Uribe was behind wiretapping conducted by the Administrative Department of Security, known by its Spanish acronym DAS, while he was president.
Several former officials and staffers of the agency have already been sentenced to serve prison time for the wiretapping, which targeted judges, opposition politicians, members of the ruling party and journalists.
The agency's former intelligence chief, Fernando Tabares, has been convicted and sentenced to more than eight years in prison, CNN affiliate Caracol reported.
"I had disagreements with many sectors of the opposition, with journalists, with judges, but I never knew of anything illegal," Uribe said Thursday. "If that were the case, I would never have any problem asking for forgiveness."
Uribe -- who was president of Colombia from 2002 to 2010 -- said accusations against him were part of a "criminal conspiracy" fueled by political opponents who wanted to send him to jail.
"It is criminal revenge because I extradited many criminals, because the policy of democratic security produced results and I have many enemies," he said.
But some people who were the subjects of the wiretapping said they did not believe the congressional commission investigating Uribe is impartial, arguing that the final result will inevitably absolve Uribe of responsibility. Lawyers representing them requested the opportunity to question Uribe during the hearing and lodged formal complaints when their requests were denied.
"Obviously they are not the ideal investigators and we have many doubts about his role in this process. The victims must be heard and they have not allowed us to be. We have to present this under international oversight," said Rep. Ivan Cepeda of the Alternative Democratic Poll party.
The lawmakers who are investigating say they will make their decision based on evidence.
"This is a public hearing requested by the former president himself. We have requested that international oversight is present, we will act within the law and the country can be assured that we are going to act with transparency," said Yahir Acuna, an investigator on the congressional committee.
Journalist Fernando Ramos and CNN en Espanol's Michael Roa contributed to this report.