With almost a third of Brazil's cabinet under investigation for alleged corruption, BBC News takes a look at some of the key words and names connected to the probe.
Car Wash (also known as Lava Jato in Portuguese)
Name given to the corruption investigation launched in March 2014 into allegations that Brazil's biggest construction firms overcharged state-oil company Petrobras for building contracts.
Former president of Brazil, removed from office on 31 August 2016 for breaking fiscal laws. While Ms Rousseff was on the Petrobras board of directors from 2003 to 2010, she has never been formally accused of corruption or self-enrichment. Operation Car Wash started during her time as president, and her supporters allege that her rivals wanted her gone because she would not shield them from the probe.
Money allegedly received by politicians involved in the Petrobras corruption scheme in exchange for handing out building contracts to companies which overcharged them.
Luiz Inacio Lula da Silva
Luiz Inacio Lula da Silva was president of Brazil from 2003 to 2011. Since he left office he has come under investigation for a number of cases of alleged wrongdoing, all of which he has denied.
In July 2016, a judge ruled there was enough evidence for Lula to stand trial for allegedly obstructing justice in connection with Operation Car Wash. Prosecutors also accused Lula of involvement in an alleged bribery scheme related to work by the construction giant, Odebrecht, in Angola.
In July 2017 he was convicted in the first of five corruption cases and sentenced to more than nine years in prison. A court found him guilty of accepting bribes in the form of a beach apartment secretly renovated for him by the construction company, OAS. He remained free pending an appeal.
Michel Temer took over as president of Brazil after Dilma Rousseff was impeached. Almost a third of his cabinet are now under investigation for alleged corruption. President Temer's name is not on the list of politicians facing investigation over the Car Wash scandal.
But on 17 May O Globo newspaper said it had recordings of Mr Temer discussing bribing an imprisoned senior politician, Eduardo Cunha, to silence him as a possible witness. Cunha was jailed for corruption, money laundering and tax evasion. Mr Temer vehemently denied the O Globo story.
Brazil's top electoral court is also hearing witnesses in a separate case over alleged illegal campaign financing. The case dates back to the 2014 presidential campaign, when Mr Temer was Ms Rousseff's running mate. The tribunal will have to decide if illegal funds were used to fund their campaign.
Brazilian-based construction giant, Latin America's largest construction conglomerate. The firm has confessed to bribing officials to secure contracts in Brazil and other countries in the region. It has agreed to pay a fine of $3.5bn (£2.8bn). Its former CEO, Marcelo Odebrecht, is serving a 19-year prison sentence for corruption. He was found guilty of paying more than $30m (£21m) in bribes to Petrobras officials in exchange for contracts and influence. He and 76 other Odebrecht officials are giving investigators information as part of a plea deal.
Brazil's state-run oil company and one of the biggest employers in Brazil with more than 78,000 workers on its books. At the centre of the corruption scandal which has engulfed Brazil for the past three years. Petrobras said in 2015 that its corruption costs hit $2bn (£1.6bn). Senior former Petrobras executives are serving lengthy prison sentences for corruption.
Sergio Moro, dubbed Super Moro by his supporters, is the federal judge in charge of the Car Wash inquiry. Judge Moro divides opinion in Brazil. Some admire him for his tenacity and willingness to go after the most influential politicians in the land, while others have questioned his methods such as leaking a phone call between former president Luiz Inacio Lula da Silva and the then-president, Dilma Rousseff.