NEW YORK — A former top FBI counterintelligence official was ordered Thursday to spend over four years in prison for violating sanctions on Russia by going to work for a Russian oligarch seeking dirt on a wealthy rival after he finished his government career.

Charles McGonigal, 55, was sentenced to four years and two months in prison in Manhattan federal court by Judge Jennifer H. Rearden, who said McGonigal harmed national security by repeatedly flouting sanctions meant to put economic pressure on Russia to get results without military force. He was also fined $40,000 and ordered to forfeit $17,500.

She imposed the sentence after a prosecutor cast McGonigal’s crime as a greedy money-grab that leveraged the knowledge he gained in his FBI career to cozy up to a notorious Russian oligarch, billionaire industrialist Oleg Deripaska, a person he once investigated.

Deripaska has been under U.S. sanctions since 2018 for reasons related to Russia’s occupation of Crimea.

Given a chance to speak, McGonigal told the judge in a sometimes shaky voice that he had a ”deep sense of remorse and am sorry for my actions.”

”I recognize more than ever that I’ve betrayed the confidence and trust of those close to me,” he said. ”For the rest of my life, I will be fighting to regain that trust.”

As he left the courthouse afterward holding hands with his wife, Pamela, he said only: ”Happy holidays everybody.”

During his August plea to a single count of conspiring to launder money and violate the International Emergency Economic Powers Act, Deripaska told the judge he accepted over $17,000 to help Deripaska collect derogatory information about another Russian oligarch who was a business competitor.

Prosecutors say McGonigal was also trying to help Deripaska get off the sanctions list and was in negotiations along with co-conspirators to receive a fee of $650,000 to $3 million to hunt for electronic files revealing hidden assets of $500 million belonging to the oligarch’s business rival.

Defense attorney Seth DuCharme urged a sentence without incarceration, citing McGonigal’s career achievements, including his work after the Sept. 11 terrorism attacks and his investigation of two deadly terrorist bombings at U.S. embassies in Africa in 1998.

But Assistant U.S. Attorney Hagan Scotten argued for a maximum five-year term, telling the judge that McGonigal was making over $200,000 annually before he retired from the FBI and that he was making over $850,000 a year in the private sector as head of global security for a prominent international corporation when he carried out his crime.

”Poverty did not motivate this crime, your honor. Greed did,” he said.

Scotten said McGonigal had one of the most important counterintelligence jobs in the world when he retired from an FBI job that should have been the ”crowning achievement in a distinguished career at the FBI.”

In a release, U.S. Attorney Damian Williams said McGonigal’s sentence was proof that anyone who violates U.S. sanctions ”will pay a heavy penalty.”

”Charles McGonigal violated the trust his country placed in him by using his high-level position at the FBI to prepare for his future in business. Once he left public service, he jeopardized our national security by providing services to Oleg Deripaska, a Russian tycoon who acts as Vladimir Putin’s agent.”

McGonigal, who lives in Manhattan, was separately charged in federal court in Washington, D.C., with concealing at least $225,000 in cash he allegedly received from a former Albanian intelligence official while working for the FBI. He faces sentencing in that case on Feb. 16. Rearden ordered him to report to prison Feb. 26.

McGonigal was special agent in charge of the FBI’s counterintelligence division in New York from 2016 to 2018. He supervised investigations of Russian oligarchs, including Deripaska.

The U.S. District Court for the District of Columbia has affirmed the sanctions against Deripaska, finding there was evidence he had acted as an agent of Putin, the Russian president.