However, the description of the Russian official closely matches that of Alexander Torshin, a deputy governor of Russia's Central Bank who was sanctioned in April.
Butina, 29, was charged with conspiring to act as an agent of Russian Federation "by developing relationships with United States persons and infiltrating organisations having influence in American politics", the Justice Department said.
Butina has not been charged with espionage or with being a member of a Russian intelligence service.
"Because Butina has been exposed as an illegal agent of Russian Federation, there is the grave risk that she will appeal to those within that government with whom she conspired to aid her escape from the United States".
Butina, 29, was arrested on Sunday and appeared before a magistrate in Washington on Monday, according to the USA justice department. Torshin was placed under sanction by the United States in April this year.
The government's motion said Butina is believed to have lived and had a personal relationship with a 56-year-old American - referred to as U.S. Person 1 - who the Federal Bureau of Investigation has determined helped her gain access to an extensive network of Americans in positions to influence political activities in the United States.
It is not known from the filing what job Butina was seeking or whether her offer of sex in exchange for the job was accepted, however. The FBI also observed her dining privately with a Russian diplomat suspected of being an intelligence operative, in the weeks before the envoy's departure from the USA last March.
She was due to appear in a Washington federal court Wednesday.
Maria Butina, who studied at American University in Washington and is a founder of the pro-gun Russian advocacy group Right to Bear Arms, was charged in a criminal complaint on Monday with conspiracy to take actions on behalf of the Russian government. She is also accused of trying to establish back-channel lines of communications for the Kremlin. Butina's attorney, Robert Driscoll, has called the allegations "overblown" and denied his client was a Russian agent.
But in court papers, prosecutors said Butina's university enrolment was a cover for her covert duties and that she suggested, falsely, on her visa application that she was no longer employed by the Russian official at the time she applied for a student visa.
Russian national and gun-rights advocate Maria Butina traded sex for a position in a special-interest organization, according to USA prosecutors who asked a judge to keep her in jail before trial because of her ties to Russian intelligence services.
Prosecutors detailed extensive private Twitter conversations and other discussions between Butina and a senior Russian official about her activities in the United States.