NEW YORK — A former high-ranking FBI counterintelligence official has been indicted on charges he helped a Russian oligarch, in violation of U.S. sanctions. He was also charged, in a separate indictment, with taking cash from a former foreign security officer.

Charles McGonigal, the special agent in charge of the FBI’s counterintelligence division in New York from 2016 to 2018, is accused in an indictment unsealed Monday of working with a former Soviet diplomat-turned-Russian interpreter on behalf of Oleg Deripaska, a Russian billionaire.

McGonigal, who had supervised investigations of Russian oligarchs, including Deripaska, before retiring in 2018, allegedly worked to have Deripaska’s sanctions lifted in 2019 and took money from him in 2021 to investigate a rival oligarch.

McGonigal, 54, and the interpreter, Sergey Shestakov, 69, were arrested Saturday. McGonigal was taken into custody after landing at John F. Kennedy International Airport. They are scheduled to appear in court in Manhattan on Monday. Both are being held at a federal jail in Brooklyn.

McGonigal and Shestakov are charged with violating and conspiring to violate the International Emergency Economic Powers Act, conspiring to commit money laundering and money laundering. Shestakov is also charged with making material misstatements to the FBI.

McGonigal was separately charged in federal court in Washington, D.C. with concealing $225,000 in payments he received from an outside source with whom he traveled to Europe.

McGonigal was required to report to the FBI contacts with foreign officials, but prosecutors allege that he hid that from his employer as he pursued business and foreign travel that created a conflict of interest with his law enforcement duties.

The U.S. Treasury Department added Deripaska to its sanctions list in 2018 for purported ties to the Russian government and Russia’s energy sector amid Russia’s ongoing threats to Ukraine.

In September, federal prosecutors in Manhattan charged Deripaska and three associates with conspiring to violate U.S. sanctions by plotting to ensure his child was born in the United States.

Messages seeking comment were left for lawyers for McGonigal and Shestakov. Lawyers for Deripaska did not immediately return an email seeking comment Monday.

The New York indictment alleges that McGonigal was introduced by Shestakov in 2018 to a former Soviet diplomat who functioned as an agent for Deripaska. That person is not identified in court papers but the Justice Department says he was “rumored in public media reports to be a Russian intelligence officer.”

According to the indictment, Shestakov asked McGonigal for his help in getting the daughter of Deripaska’s agent an internship with the New York Police Department. McGonigal agreed, prosecutors say, and told a police department contact that, “I have interest in her father for a number of reasons.”

The Justice Department says McGonigal also hid from the FBI key details of a 2017 trip he took to Albania with a former member of that country’s intelligence service who had given him the $225,000.

For instance, prosecutors say, he failed to identify the person as his traveling companion or reveal that housing for him would be free.

Once there, according to the Justice Department, he met with Albania’s prime minister and discouraged him from awarding oil field drilling licenses in the country to Russian front companies. McGonigal’s Albanian contacts had a financial interest in those decisions, prosecutors say.