May 14 (UPI) -- Just five months before Brazil's October elections, the presidential campaign of right-wing Sen. Flávio Bolsonaro has become entangled in what authorities describe as the country's largest recent banking fraud case.

According to reports published by Intercept Brasil, Bolsonaro negotiated a multimillion-dollar sponsorship deal to finance a film about his father, former President Jair Bolsonaro, with a banker now jailed on suspicion of leading a criminal organization involved in financial fraud.

The Brazilian news outlet released audio recordings and messages allegedly tied to negotiations between the senator and Daniel Vorcaro, owner of the collapsed Banco Master. Vorcaro is being held in pretrial detention as part of a financial and political scandal that has expanded to include Brazilian politicians and judges.

The scandal erupted after Brazil's Federal Police intercepted Vorcaro's phone messages, which reportedly reveal a close relationship between the two men -- with Flávio Bolsonaro referring to the banker as "brother."

In the conversations, Bolsonaro allegedly pressured Vorcaro to release payment for a sponsorship worth 134 million reais, or about $26 million, according to Brazilian outlet G1 Globo. The funds were intended for the Hollywood production of The Dark Horse, a biographical film aimed at improving Jair Bolsonaro's public image.