Rubio testifies in trial of ex-Florida congressman allegedly hired by Maduro government to lobby for Venezuela

"I was skeptical," said Rubio during his testimony, according to The Associated Press, adding that the Maduro government was full of "double dealers" who were constantly pitching plans to betray Maduro. 

"But if there was a 1% chance it was real, and I had a role to play alerting the White House, I was open to doing that," he added. 

Within days, borrowing talking points provided by Rivera, Rubio wrote and delivered a speech on the Senate floor signaling the U.S. would not retaliate against Venezuelan government insiders who worked to push Maduro from power, the AP reported. 

"He provided me with insight into some of the key phrases that regime insiders would've wanted to hear to know this was serious," Rubio testified. "No vengeance, no retribution." 

In the indictment against Rivera, there's no indication that Rubio acted improperly as a senator at the time. 

The allegations come in connection to a $50 million consulting contract Rivera signed with Venezuela's socialist government. 

The indictment alleges Rivera, at the start of the Trump administration, was part of a conspiracy to lobby on behalf of Venezuela to lower tensions with the U.S., resolve a legal dispute with a U.S. oil company and end U.S. sanctions against the South American nation - all without registering as a foreign agent. 

As part of his work, Rivera and his co-defendant are accused of trying to arrange meetings for then-Foreign Minister Delcy Rodriguez - now Venezuela's acting president - in Dallas, New York, Washington and Caracas, Venezuela, with White House officials, members of Congress and the chief executive officer of Exxon Mobil. 

To cloak their activities, prosecutors said, the co-defendants and others set up a chat group called MIA - for Miami - in which they used Spanish-language code words like "Little Cuban" for Rubio, "The Lady in Red" for Rodriguez and "melons" for millions of dollars. 

"This case is about two things: greed and betrayal," prosecutor Roger Cruz said in his opening statement Monday. "The evidence will show that for $50 million these two defendants made a pact to secretly lobby for Nicolás Maduro," as well as for Rodriguez. 

Rivera, 60, counters that his one-man firm, Interamerican Consulting, was hired by an American subsidiary of Venezuela's state-owned oil company - not the company itself - and therefore did not need to register as a foreign agent. 

His three-month contract, his attorney says, was focused exclusively on luring Exxon back to Venezuela - commercial work that is generally exempt from the Foreign Agents Registration Act. 

Separate and wholly distinct from that consulting work were his efforts with the Venezuelan opposition to pave the way for Maduro's exit, Rivera's defense said. 

Fox News' Gillian Turner, Fox News Digital's Danielle Wallace and The Associated Press contributed to this report.