Colombian President Juan Manuel Santos apologized Tuesday over funding for his 2010 election campaign from scandal-plagued Brazilian construction firm Odebrecht, saying he had been unaware of the payments at the time.
Santos, the winner of the 2016 Nobel Peace Prize, posted an angry video on Twitter after the campaign's finance director said Odebrecht had paid for two million Santos posters.
Odebrecht is caught up in a series of kickback scandals across Latin America that originated during an investigation into massive corruption at Brazilian state oil company Petrobras.
In Colombia, an ongoing probe into Odebrecht payments to the Santos campaign threatens to tarnish the president just as he seeks to implement his signature peace deal to end a half-century conflict with the FARC guerrillas.
"I did not authorize or have any knowledge of (the payments), which were made in direct violation of the ethical norms and accounting procedures I demanded be put in place for the campaign," Santos said from his office.
"I apologize to all Colombians for this shameful incident, which never should have happened and of which I have only just learned," he said in the video, sporting a white dove lapel pin.
Santos, 65, called for an investigation and said "those responsible for any act of corruption must be punished."
The comments came just after the airing of a radio interview with Roberto Prieto, the finance director of Santos's first presidential campaign in 2010 and manager of his 2014 re-election campaign.
Prieto told Blu Radio that Odebrecht paid for Santos campaign materials in 2010.
"They told me, 'We need to purchase two million posters.' I said, 'Who's paying for that?' 'Odebrecht will pay. Send the bill to Odebrecht.' And that's what I did," he said, without specifying with whom he had the alleged conversation.
He said that Santos "had nothing, absolutely nothing, to do with" what he called the "irregular transaction."
He added that the president's 2014 campaign -- the current target of the prosecutors' investigation -- had taken no money from any company.
The probe was opened after a former senator alleged Odebrecht paid a $1 million bribe to the president's 2014 campaign in hopes of securing a lucrative road-building contract.
Santos denied the allegation at the time.
Odebrecht, the largest construction company in Latin America, agreed in December to pay a record $3.5 billion settlement over revelations that it paid massive bribes to win juicy contracts in 12 countries in Latin America and Africa.