Former United States congressman David Rivera has been sentenced to 10 years in federal prison for secretly lobbying American officials on behalf of Venezuela’s government.

United States district judge Melissa Damian handed down the sentence on October 2 in Miami. A jury convicted Rivera in May of failing to register as a foreign agent and conspiracy to commit money laundering, after a trial lasting six to seven weeks.

Prosecutors said Rivera and consultant Esther Nuhfer obtained a 50-million-dollar contract with a subsidiary of Venezuela’s state oil company PDVSA, then lobbied officials including then-senator Marco Rubio without registering under the Foreign Agents Registration Act. Prosecutors said the pair received about 20 million dollars.

Rivera, a 61-year-old Republican who represented South Florida in the House from 2011 to 2013, pleaded not guilty. His lawyers said he was helping Venezuela’s opposition, not the Maduro government, and plan to appeal. They have also sought a presidential pardon.

The judge rejected that argument, saying there was no dispute the money came from the Maduro regime.