The US Justice Department had not said in what case Butina might be asked to cooperate, according to the Daily Beast.
The outlet added, that Butina’s boyfriend, activist Paul Erickson, had reportedly been notified by US federal prosecutors that he might be prosecuted for acting as an unregistered foreign agent of Russia just like Butina.
READ MORE: Lavrov: Russia's Maria Butina Under Harsh Conditions, Tortured by US Authorities
The court documents, made public on Friday, read that the motion should remain sealed because its release "would pose a risk to the defendant’s safety and the safety of the community," according to the outlet.
The Daily Beast added that previous court papers, submitted in September, showed US federal agents had transported Butina to the US Attorney’s Office in Washington, D.C., at least twice.
Butina subsequently cooperated with the investigators, pleading guilty in front of a US federal judge to one count of conspiracy to act as a foreign agent on Thursday.