Embattled Sen. Robert Menendez told CNN on Monday that his failure to reimburse almost $60,000 in flights on a political donor’s plane was an oversight and that he righted the mistake “when it came to my attention.”

The New Jersey lawmaker said the flights to the Dominican Republican on the private plane of his friend and campaign donor Dr. Salomon Melgen took place while he was traveling extensively as chairman of the Democratic Senatorial Campaign Committee. “It unfortunately fell through the cracks,” Menendez said.

He added: “I personally paid for them in order to meet my obligations. … When it came to my attention, I did what was right.”

Menendez’s office has acknowledged that the senator did not repay Melgen for the trips until after a New Jersey Republican official complained to the Senate Ethics Committee.

The plane trips have come under scrutiny because Melgen’s ophthalmology office was raided by the FBI last week. Subsequently, the New York Times reported that Menendez went to great lengths to help Melgen’s business interests in the Dominican Republic, including pressing State Department officials to help force the Dominican government to honor a contract with a port security company associated with Melgen.

CNN reporter Dana Bash said she also spoke to Menendez off camera about the allegation that he worked to improperly aid Melgen’s business. Bash said Menendez said his actions had nothing to do with his friendship but were motivated by “what was right for the policy of the United States.”

Menendez on Monday also denounced as “smears” allegations from conservative news sites that he had sex with prostitutes while on trips to the Dominican Republic with Melgen.

“It’s amazing to me that anonymous, nameless, faceless individuals on a website can drive that type of story into the mainstream,” Menendez said.

He continued, “The bottom line is all of those smears are absolutely false.”

Menendez also alluded to reports that the person who anonymously tipped off conservative websites to alleged trysts with prostitutes has refused to meet with the FBI and ethics watchdogs such as Citizens for Responsibility and Ethics in Washington. The Miami Herald also reported Monday that attempts to locate the alleged prostitutes were unsuccessful.

“Now, nobody can find them. No one ever met them. No one ever talked to them, but that’s where we’re at,” Menendez said.