(CNN) - 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.
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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. CNN is not able to verify Fernandez's story.
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."
Another issue has to do with whether Menendez advocated on Capitol Hill on behalf of ICSSI - a port security company in which Melgen has a stake. The company had a contract to screen cargo that went through Dominican ports, but Menendez argued last July during a Senate subcommittee hearing that Dominican authorities didn't want to "live by" the contract.
Asked if he used his influence to help Melgen, he said: "I have always advocated for issues and I have advocated for policies, and that's what I have done across the board."
– CNN's Jim Acosta, Adriana Hauser, Alan Duke, Kevin Liptak and Ashley Killough contributed to this report.