A conservative US political activist romantically linked to the Russian agent Maria Butina has been indicted by a federal grand jury on wire fraud and money laundering charges, the US attorney’s office in South Dakota has said.

Paul Erickson, 56, was indicted on 11 counts of wire fraud and money laundering on Tuesday and pleaded not guilty to the charges in an appearance before US magistrate judge Mark Moreno, the office said. Erickson’s attorney did not immediately respond to a request for comment.

Erickson is a well-known figure in Republican and conservative circles and was a senior official in Pat Buchanan’s 1992 Republican presidential campaign. He was romantically linked to Butina, a 30-year-old native of Siberia, who pleaded guilty in December to conspiracy.

Butina admitted working with a top Russian official to infiltrate the powerful National Rifle Association gun rights group and to make inroads with American conservatives and the Republican party as an agent for Moscow.

A former graduate student at American University in Washington, Butina had publicly advocated for gun rights. She was the first Russian to be convicted of working to influence US policy during the 2016 presidential race.

Erickson’s indictment did not refer to Butina by name, but it indicates he made a payment of $8,000 to an “MB” in June 2015 and another payment of $1,000 to MB in March 2017. The indictment also indicates he paid American University $20,472.09 in June 2017.

The indictment against Erickson alleges that between 1996 and 2018 he made “false and fraudulent representations” to people in South Dakota and elsewhere about his business schemes in an effort to convince potential investors to give him money, the US attorney’s office said.

Erickson owned and operated Compass Care, Investing with Dignity, and an unnamed venture to develop land in the Bakken oilfields in North Dakota, it added.

He faces a maximum penalty of 20 years in prison on each count as well as possible fines. He was released on bond and no date has been set for a trial.