A U.S. lawmaker employed as an unpaid intern in his Senate office an illegal immigrant who was a registered sex offender, now under arrest by immigration authorities, The Associated Press has learned. The Homeland Security Department instructed federal agents not to arrest him until after the Nov. 6 Election Day, a U.S. official involved in the case told the AP.

AP FILE - This Sept. 27, 2012 file photo shows Sen. Robert Menendez, D-N.J. speaking in Sayreville, N.J.

Luis Abrahan Sanchez Zavaleta, an 18-year-old immigrant from Peru, was arrested by Immigration and Customs Enforcement agents in front of his home in New Jersey on Dec. 6, two federal officials said. Sanchez, who entered the country on a now-expired visitor visa from Peru, is facing deportation and remains in custody. The officials spoke on condition of anonymity because they were not authorized to discuss details of Sanchez's immigration case.

A spokesman for the Homeland Security Department, Peter Boogaard, said in an email to the AP that ICE followed standard procedures working with local prosecutors before taking what he called "appropriate enforcement action." Boogard also said AP's report was "categorically false." He did not immediately respond to a request to specify what might be false.

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