To an extraordinary extent, the Brazilian investment bank BTG Pactual – described by Dan Horchjan of the New York Times as one of the rare Latin American firms of its kind that rival the top Wall Street and European banks – owes its existence, and its years of spectacular success, to a single individual: its self-made founder and CEO, André Esteves. As people in his line of work go, he’s been an unusually prominent figure in Brazil. “More than any other financier,” Horchjan wrote recently, Esteves “was the face of Brazil’s global ambitions during the country’s recent, short-lived boom – in a hurry to grow and unafraid to compete against anyone, anywhere.” Esteves, whom Bloomberg has called the “golden boy” of Brazilian banking, used to say that the letters BTG in the name of his firm stood for “better than Goldman.”

To be sure, the company has had its share of controversies. In 2007, Esteves was convicted of insider trading. In 2013, BTG Pactual partner Charles Rosier was found guilty in the largest insider-trading case in French history. Other accusations of questionable conduct have been made by high-profile observers but not acted upon. In 2006, for example, Esteves sold BTG Pactual’s predecessor, named simply Pactual, to UBS, the Swiss financial-services company, for $2.6 billion (becoming Brazil’s youngest self-made billionaire), only to buy it back three years later for a smaller sum and combining it with his new firm, BTG, to create BTG Pactual. More recently, Esteves and a BTG Pactual director, Huw Jenkins, were sued in a Hong Kong court for $20 million for making “fraudulent misrepresentations” to secure a deal. Three times since 1999, BTG Pactual has been taken to court by Brazilian authorities for shifting money around to mask profits and thus shirk taxes.

But all of this is now mere background – perhaps even just a series of footnotes. We talked yesterday about the arrest and conviction of Latin America’s #1 construction contractor, Marcelo Odebrecht, as part of Operation Car Wash, the massive probe into corruption surrounding Brazil’s state-owned oil firm, Petrobras. After his arrest last June, Odebracht tried to slip a note to his lawyers asking them to destroy e-mails that implicated Esteves. The note found its way into the wrong hands, so that Odebrecht inadvertently ended up fingering Esteves. Esteves’s name was also mentioned in a recorded conversation in which suspects in Operation Car Wash – notably Delcidio do Amaral, the top-ranking Senator in the Workers’ Party – discussed plans to pay a potentially unfriendly witness, Nestor Cervero, the former head of Petrobras’s international division, to leave the country. And police found a note suggesting that BTG Pactual had bribed a congressmen to the tune of millions of dollars. On November 25, Esteves was arrested – and so was Amaral, who became the first sitting legislator to be swept up as a result of the Petrobras probe.

In a January report on his downfall, the Times‘s Horchjan highlighted “its apparent senselessness.” He quoted analyst Luis Miguel Santacreu as saying that BTG Pactual’s deals with Petrobras and the Brazilian government “were relatively small and had nothing to do with the bank’s core business, which was very profitable….They didn’t need any of these deals to keep on growing.” Felipe Monteiro, a French professor of strategy, made the same point in a comment to Bloomberg: “He epitomizes the idea of a private, successful, entrepreneurial generation of Brazilian bankers,” and so his involvement in “the most classic type of old politics is somehow strange.” It’s especially strange given that BTG Pactual actually lost money on its government deals even as it was turning tidy profits on its core, non-state-related business.

As Marcelo Odebrecht’s ruin sent the Brazilian construction sector tumbling, so the destruction of Esteves’s career shook the country’s financial sector to its roots. Now BTG Pactual’s shares are worth half of what they were. Its bonds are considered junk.