TIMELINE-Key moments in Brazil's Petrobras corruption probe
By Caroline Stauffer
July 24 (Reuters) - Prosecutors and federal police in Brazil unearthed the country's largest-ever corruption scandal by tying a ring of black-market money changers to a price-fixing and political kickback scheme at state-run oil firm Petrobras .
Executives from two dozen engineering firms are accused of inflating the value of service contracts and funneling the excess funds into their own bank accounts and to political parties, including President Dilma Rousseff's Workers' Party.
On Friday, prosecutors presented formal charges against the chief executive officer of Latin America's largest engineering firm, Odebrecht SA, and other senior executives who were arrested on June 19.
Below are key moments of Brazil's largest-ever corruption investigation, which prosecutors in the southern city of Curitiba expect to continue for another two years. A separate investigation into politicians is also advancing in Brasilia.
March 20, 2014
Federal police arrest the former head of Petrobras' refining and supply department, Paulo Roberto Costa, the result of an investigation that started when they noticed Costa had been given a Range Rover by convicted money changer Alberto Youssef.