Brazilian shares are falling Thursday sharply after news reports that the nation's President Michel Temer was caught on tape supporting payment of a bribe to make a corruption probe go away.

The iShares Brazil Fund  (EWZ) - Get Report, the largest exchange-traded fund based on the nation's stock market, fell 17% to $39.14.

The Guardian newspaper reported that the tape surfaced as part of a plea bargain agreement with brothers Joesley and Wesley Batista, who run JBS, Brazil's biggest meat-packing company. It said the tape also incriminate several other politicians.

The tape is the most recent part of a multi-year corruption probe called "Operation Carwash." More than 80 people have been charged with bribery and money laundering to date.

In April Moody's  downgraded debt issued by units of Brazil's Odebrecht construction and energy conglomerate. The securities are notes issued by Odebrecht Finance  (OFL) and guaranteed by Odebrecht Engenharia e Construcao (OEC) - Get Report .

OEC is Brazil's largest construction company, with $10.5 billion in revenue for the year ending last September. Its parent company also owns oil and gas company Braskem

The downgrade was partially caused by problems stemming from a corruption probe into Odebrecht and other companies. Odebrecht stands accused of forming a clandestine group called the division of structured operations - also knowns as the carwash - that served only to make bribery payments.

The scandal led to the arrest of Odebrecht CEO Marcelo Odebrecht, who was sentenced by Brazilian courts to 30 years in prison and then reached a plea deal.

The investigations reached to far corners of the business and political communities, and at one point last year former Brazilian President Luiz Inacio Lula da Silva was interrogated as part of related inquiries involving Petrobras.