Secretary of State Marco Rubio is scheduled to testify Tuesday in the federal trial of former Miami congressman David Rivera, who faces charges of secretly lobbying for Venezuela's government during the first Trump administration without registering as a foreign agent.

Rivera, 60, and an associate are charged in an 11-count indictment with money laundering and failing to register as foreign agents. Prosecutors allege Rivera leveraged his Republican connections to push the White House to abandon its hard line against Venezuela's socialist government under then-President Nicolás Maduro. Rivera, who was once Rubio's roommate in Florida, allegedly secured a $50 million lobbying contract from Venezuela's state oil company PDVSA through then-Foreign Minister Delcy Rodríguez.

According to the indictment, Rivera and Rubio met at the senator's Washington home on July 9, 2017, where Rivera discussed his work with Venezuelan media tycoon Raúl Gorrín, who allegedly served as Rivera's conduit to the Maduro government. Prosecutors say Rivera viewed Rubio as a key ally in his White House outreach efforts and told Gorrín that Maduro would have to pay for arranging meetings with the senator.

Rubio's testimony marks a rare occurrence of a sitting Cabinet member testifying in a criminal trial. While Rubio faces no charges and the indictment contains no allegations of improper conduct by him, prosecutors say Rivera believed the senator's support was crucial to his lobbying efforts. The case also involves allegations that Rivera worked with Texas Republican Rep. Pete Sessions to arrange meetings with Exxon Mobil executives on Venezuela's behalf.

Rivera's defense attorneys argue he was hired by an American subsidiary of PDVSA, not the Venezuelan government directly, and therefore did not need to register as a foreign agent. They contend his consulting work focused on positioning Venezuelan-owned Citgo in the U.S. energy market and was separate from any diplomatic efforts. Rivera has denied all wrongdoing and previously faced other allegations, including secretly funding a Democratic candidate in a 2012 congressional race, though federal prosecutors dropped that case last year.