The former head of counterintelligence for the FBI’s New York City office was arrested over the weekend on charges of money laundering and violating sanctions on Russia, three senior law enforcement officials told NBC News.

An FBI spokesman confirmed the arrest of Charles McGonigal, who was apprehended at JFK airport in New York on Saturday after returning on a flight from the Middle East. 

Prosecutors allege that McGonigal worked with Russian oligarch Oleg Deripaska, Deripaska associate Sergey Shestakov, and a third person to investigate a rival Russian oligarch in return for payments from Deripaska.

According to prosecutors, McGonigal, Shestakov, and a third person tried to conceal Deripaska’s involvement through shell companies, forged signatures, and other means.

The activity allegedly occurred three years after McGonigal’s 2018 retirement from the FBI.

U.S. Attorney Damian Williams said, “As alleged, Charles McGonigal, a former high-level FBI official, and Sergey Shestakov, a Court interpreter, violated U.S. sanctions by agreeing to provide services to Oleg Deripaska, a sanctioned Russian oligarch. They both previously worked with Deripaska to attempt to have his sanctions removed, and, as public servants, they should have known better.”

FBI Assistant Director in Charge Michael J. Driscoll said, “The FBI is committed to the enforcement of economic sanctions designed to protect the United States and our allies, especially against hostile activities of a foreign government and its actors. Russian oligarchs like Oleg Deripaska perform global malign influence on behalf of the Kremlin and are associated with acts of bribery, extortion, and violence.”

The Treasury Department sanctioned Deripaska for “having acted or purported to act on behalf of, directly or indirectly, a senior official of the Government of the Russian Federation and for operating in the energy sector of the Russian Federation economy,” according to the Justice Department. 

McGonigal was named special agent in charge of the Counterintelligence Division for the New York Field Office in 2016, after serving as the section chief of the Cyber-Counterintelligence Coordination Section at FBI headquarters.

McGonigal joined the FBI in 1996, and was first assigned to the New York Field Office, where he worked on Russian foreign counterintelligence and organized crime.

During his tenure in New York, he worked on the TWA Flight 800 investigation, was assigned to the task force investigating scientist Wen Ho Lee, investigated the 1998 terrorist bombings of the U.S. Embassies in Tanzania and Kenya, and investigated the Sept, 11, 2001 terror attacks.

McGonigal’s attorney did not immediately respond to a request for comment.