Joao Vaccari, treasurer of Brazil's ruling Workers' Party, is escorted by police as he arrives to a legal medical institute in Curitiba

Joao Vaccari, treasurer of Brazil’s ruling Workers’ Party, is escorted by police as he arrives to a legal medical institute in Curitiba April 15, 2015. Brazilian police on Wednesday arrested Vaccari, moving an investigation of graft and political kickbacks at state-run oil company Petrobras closer to President Dilma Rousseff’s inner circle. Vaccari denied the accusations last week before a congressional inquiry commission. REUTERS/Rodolfo Buhrer