In February 2014, an investigation by Brazilian Federal Police called "Operation Car Wash" placed Petrobras at the center of what may be the largest corruption scandal in Brazil's history.[19][20] On 14 November 2014 police raids across six Brazilian states netted prominent Brazilian politicians and businessmen—including some Petrobras directors—who were placed under investigation in regards to "suspicious" contracts worth $22 billion.[19][20] It was alleged that graft occurred while President Rousseff was part of the board of directors of state-owned energy company Petrobras from 2003 to 2010. No evidence that Rousseff herself was involved in the scheme has been found, and she denies having any prior knowledge of it.[21] However, Brazilians became upset with the government and called for Rousseff's impeachment regardless.[22] Further investigation found that there were various offshore accounts and collections of art that were held by those involved in the controversy.[23]