Colombia’s public prosecutor has called for an investigation into whether former president Alvaro Uribe was linked to a massacre carried out by paramilitaries in 1997.

The prosecutor’s office asked the supreme court to look into whether Uribe was somehow connected to the attack that left 15 peasants dead in the hamlet of El Aro, in the state of Antioquia, near Medellin.

At the time, victims said armed men burned homes, raped women and killed farmers indiscriminately during the two-day rampage. They also said they saw a government helicopter circling overhead as the carnage took place.

Uribe was president until 2010, and is now a senator who helps lead the South American country’s right wing. He was governor of Antioquia at the time of the massacre.

A local court earlier this year requested a similar probe of Uribe’s possible involvement, citing the presence of the government helicopter at the scene of the killing.

On Tuesday, Uribe dismissed the public prosecutor’s request as a political ploy designed to influence upcoming elections.

“I’m used to being slandered, especially around election time,” he said.