The trial of former U.S. Congressman David Rivera started Monday in Miami as the Florida Republican faces charges that he illegally lobbied American officials on behalf of Venezuelan interests without registering as a foreign agent, according to Reuters.

Federal prosecutors say Rivera was paid $20 million in 2017 by Venezuelan state-owned companies to try to improve ties between Washington and the government of then-President Nicolas Maduro and to prevent additional U.S. economic sanctions. Rivera, who served in the U.S. House of Representatives from 2011 to 2013, has pleaded not guilty to 10 criminal counts, including conspiracy to commit money laundering, Reuters reported.

The case could also draw attention to the role current Venezuelan interim President Delcy Rodriguez allegedly played in the lobbying effort during the opening months of President Donald Trump’s first term. Prosecutors allege Rodriguez directed U.S. refiner Citgo, a subsidiary of Venezuelan state oil company PDVSA, to sign a consulting contract with Rivera’s company to compensate him.

Prosecutors say Rivera arranged a meeting in April 2017 between Rodriguez, then Venezuela’s foreign minister, and a U.S. congressman from Texas. In June of that year, he allegedly arranged a meeting between a Venezuelan businessman and a U.S. senator from Florida. The indictment does not identify those figures by name, but Reuters reported that Rivera’s lawyers identified the businessman and senator in court papers as Raul Gorrin and Marco Rubio.

Rivera’s defense lawyer, Ed Shohat, told Reuters that Rivera was not required to register under FARA because he was paid by a U.S. affiliate of PDVSA. In court filings, Rivera’s lawyers have also argued that he was working to help Venezuela’s opposition remove Maduro from power.

Read more at Reuters