Senate Foreign Relations Committee Chairman Robert Menendez is striking back against new corruption allegations regarding his ties to two Ecuadorian bankers who are accused of defrauding account holders in Ecuador to the tune of $100 million.

NBC News reported Thursday that the FBI has expanded its probe into Menendez to include his advocacy on behalf of William and Roberto Isaias, two Ecuadorian nationals living in Coral Gables, Fla. The Isaias brothers were convicted in absentia in Ecuador for embezzling millions as their bank, Filanbanco, collapsed in the 1990s. Menendez made phone calls and wrote letters on supporting the Isaias brothers’ desire to avoid extradition to their home country, NBC News reported, citing unnamed officials.

Family members of the Isaias brothers contributed $10,000 to Menendez’s 2012 Senate campaign and more than $100,000 to the Democratic Party that year, according to the NBC News report.

In a statement Thursday evening to The Daily Beast, Menendez spokeswoman Tricia Enright denied the senator had been involved in any quid pro quo related to the Isaias brother’s visa or asylum status and said the allegations were part of a larger effort to discredit the New Jersey Democrat.

“A year after a false smear campaign was launched against Sen. Menendez, once again we see anonymous sources making outlandish allegations,” said Enright.

Enright said Menendez’s office was still reviewing what actions the senator has taken regarding the Isaias matter, but maintained that any advocacy Menendez offered to the bankers was based on the merits of the case.

“Our office works each year with literally hundreds of individuals and families from across the country who are seeking help with the immigration process. We review each and every request we receive, and if we feel any inquiry is appropriate, we make it,” she said. “In this particular case, Sen. Menendez believed the Isaias family had been politically persecuted in Ecuador, including through the confiscation of media outlets they owned which were critical of the government.”

The FBI has never informed Menendez that the Isaias case is part of their investigation into his activities, she said. “We are not aware of any inquiry into the senator’s actions on this matter.”

Roberto Isaias denied to NBC News that the brothers have any relationship with the senator. The FBI has been investigating Menendez’s relationship with Florida eye doctor Salomon Melgen, a major campaign donor.

Federal investigators are also looking into whether Menendez improperly intervened in a billing dispute with Medicare and a separate port-security deal in the Dominican Republic, for which Melgen’s company was competing. Menendez repaid Melgen $58,000 last year after it was revealed the senator had taken three plane rides on Melgen’s jet to a Dominican Republic resort.