The former CEO of Brazilian construction giant Odebrecht says the company helped finance the campaign of Peru's former President Ollanta Humala.

In testimony this week to prosecutors, Marcelo Odebrecht said the company contributed $3 million to Humala, who was elected in 2011.

The Odebrecht construction company is at the center the biggest corruption probe in Brazil's history. The investigation, known as Operation Car Wash, has already unveiled billions of dollars in kickbacks and bribes paid to politicians by Brazilian companies.

A former Odebrecht executive also testified this week that the company donated $1.5 million to the campaign of El Salvador's Mauricio Funes, who was president of that Central American country from 2009 to 2014.