Democratic Sen. Robert Menendez, in an exclusive television interview with CNN on Monday, denied claims that he had engaged in parties with prostitutes during trips to the Dominican Republic.
"The bottom line is all those smears are absolutely false," Menendez told CNN Chief Congressional Correspondent Dana Bash on Capitol Hill.
The New Jersey Democrat is also battling allegations of improper travel with a generous donor whose plane he took to the Dominican Republic and who has business ties in the Caribbean nation.
Shortly before Election Day, a conservative online publication cited three unidentified sources who claimed Menendez had flown on private planes to the Caribbean and during the trips had sex parties with prostitutes.
Menendez, however, fired back on Monday and called the prostitute allegations "unsubstantiated."
"The smears that right-wing blogs have been pushing since the election -- and that is totally unsubstantiated and it's amazing to me that anonymous, nameless, faceless individuals on a web site can drive that type of story into the mainstream," he said.
"But that's what they've done successfully. Now nobody can find them. No one ever met them. No one ever talked to them but that's where we're at," he added.
His comments came as one of the women accused of being a prostitute involved with Menendez denied those claims in a Spanish-language interview released on Monday.
The woman, identified as 21-year-old Yaneisi Fernandez, says she's never met Menendez or worked as a prostitute.
"I've never participated in those activities, I don't know those people or that man," Fernandez told Univision.
As for the other allegations, Menendez has faced scrutiny for taking multiple flights in 2010 with the donor, Dr. Salomon Melgen, a South Florida ophthalmologist. However, he didn't pay for the flights-valued at $58,500-until January 4 of this year.
Asked Monday why it took so long to repay the money, Menendez said he was having a busy year and chalked it up to an oversight.
"I was in a big travel schedule in 2010 as the chair of the (Democratic Senatorial Campaign Committee), plus my own campaign getting ready for a re-election cycle and in the process of all of that, it unfortunately fell through the cracks," he told CNN.
"When it came to my attention that payment had not taken place, I personally paid for them in order to meet my obligation," he added.
Pressed further on how he managed to overlook such a big chunk of money, Menendez said, "The bottom line is when it came to my attention, I paid for it."
"There were a series of flights that were alleged," he continued. "Several of them were shown not to be the case, but after the election when I got to look at the allegations and I did my own self-inspection, I ultimately came forward. As a matter of fact, one of those flights I self reported."
The latest allegations are based on documents published by a non-partisan Washington watchdog group - Citizens for Responsibility and Ethics in Washington, known as CREW. The group published an e-mail this week it received last April from a man who identified himself as Peter Williams.
"My duty as a U.S. citizen obligates me to report what I consider to be a grave violation of the most fundamental codes of conduct that a politician of my country must follow," the tipster wrote.
E-mails sent by Williams included statements from women detailing what they said were sex parties in a house and on a yacht in the Dominican Republic owned by Dr. Salomon Melgen, a south Florida ophthalmologist.
Williams suggested that he and the women "will be willing to testify" about the allegations if their safety was guaranteed.
The documents released by CREW identify Yaneisi Fernandez as one of the prostitutes connected to Menendez, allegations she told Univision were completely false.
"No, that is completely false. I don't even know that man. Not even through TV have I seen him," she said. CNN is not able to verify Fernandez's story.
A translation of the Univision interview with Fernandez was e-mailed to reporters by staffers in Menendez's Senate office. The translation was confirmed to be accurate by CNN.
An official working for Menendez told CNN the video "is pretty damning to those who continue to peddle 'Pete Williams'' allegations and all this garbage."
"Real people get hurt," the official said.
CNN's Jim Acosta, Adriana Hauser, Alan Duke, Kevin Liptak and Ashley Killough contributed to this report.