Immigration and Customs Enforcement (ICE) agents arrested an unpaid intern for Sen. Robert Menendez’s (D-N.J.) office, who was a registered sex offender and an illegal immigrant.

The intern, Luis Abrahan Sanchez Zavaleta, was arrested in New Jersey last Thursday, as first reported by The Associated Press. Sanchez came to the United States on an expired visitor visa from Peru. 

{mosads}Members of Menendez’s staff were informed about Sanchez shortly after he was arrested. Sanchez told law enforcement officials that he worked on immigration issues for Menendez, the report said.

According to the Hudson County, N.J., prosecutor’s office, Sanchez was required to register as a sex offender in 2010 after breaking the law. Because Sanchez was a minor when he was prosecuted, the exact charges are not public record.

On MSNBC on Wednesday, shortly after the AP report was published, Menendez denied knowledge of Sanchez’s status as an illegal immigrant until today.

“I didn’t know anything about the young man’s status until this Monday so — actually, before I came onto this program. My staff knew about it on Monday, I didn’t know it until right before I came onto your program,” Menendez said.

Menendez stressed that Sanchez was an “unpaid college intern.”

“So it’s not like he’s a staff, paid person. We have a whole bunch of college interns. We give them some experience in the office,” Menendez said. “They answer phones, they do some mail and most of the time they attend lectures of different entities in the federal government that they bring to the office, so it’s not like an employee, number one.

“Number two is there’s no way we could know about his status, we ask about his status. Number three there’s no way we could know about any allegation of, as a juvenile, of what his background would be in terms of any criminality,” he added.

Menendez has been a strong proponent of immigration reform and said the news spoke “volumes of how much we need” to address the issue.