Former Colombian President Juan Manuel Santos is refuting accusations that money from corruption-tarnished Brazilian construction giant Odebrecht made its way into his 2014 presidential re-election campaign.

The ex-chief of state told reporters Wednesday there is “not a single proof” that any unethical conduct took place after testifying for two hours before Colombia’s National Electoral Council.

Santos said he has largely kept silent for three years even as accusations swirled against him in order to avoid “politicizing justice.”

The National Electoral Council is conducting a preliminary investigation against the ex-president but no charges have been filed.

Santos is widely known for signing a historic 2016 peace deal with leftist rebels.

High-ranking politicians across Latin America have come under fire for taking money from Odebrecht in exchange for lucrative public works contracts.