Two of South America's wealthiest brothers, the Bolivian-born airline magnates German and Jose Efromovich, were arrested Wednesday in Brazil as part of the country's sweeping anti-corruption probe, "Operation Car Wash."

The brothers are the biggest shareholders in Colombian airline Avianca, the second-largest in Latin America.

However, prosecutors said their investigation was not related to the airline but to contracts another from Efromovich firm, the shipbuilder EISA -- Estaleiro Ilha, made with Transpetro, a subsidiary of Brazilian state-run oil company Petrobras.

The brothers are suspected of paying 28 million reals (about $15 million at the time) in bribes from 2009 to 2013 to Transpetro's former chief executive, Sergio Machado, in exchange for lucrative contracts with the transport and logistics firm, prosecutors said in a statement.

Germán Efromovich (pictured February 2020) and his brother Jose are suspected of paying 28 million reals (about $15 million at the time) in bribes from 2009 to 2013 to Transpetro's former chief executive in exchange for lucrative contracts
Germán Efromovich (pictured February 2020) and his brother Jose are suspected of paying 28 million reals (about $15 million at the time) in bribes from 2009 to 2013 to Transpetro's former chief executive in exchange for lucrative contracts AFP / DANIEL MUNOZ

Investigators raided homes and four businesses belonging to the brothers, who were arrested in Sao Paulo, prosecutors said.

Because of the coronavirus pandemic, the brothers were assigned to house arrest, according to a court ruling seen by AFP.

German Efromovich, 70, is a former chairman of the board at Avianca, but was forced from the post last year.

He and Jose, 65, hail from a Polish Jewish family that emigrated to South America after World War II.