Rep. George Santos, R-N.Y., speaks to reporters on Capitol Hill in Washington on Wednesday. Jabin Botsford./The Washington Post

Rep. George Santos, R-N.Y., who was charged earlier this month with a host of financial crimes, is now serving as the treasurer for his own campaign and several affiliated committees, according to filings made Friday by the committees with the Federal Election Commission.

The congressman’s unusual move to become his own campaign treasurer followed his indictment on 13 counts of financial crimes last week by federal prosecutors in New York. His colleagues also referred a resolution to the House Ethics Committee this week to expel him from Congress. Santos, 34, has vowed not to resign, maintaining that he will prove his innocence and seek reelection next year.

The embattled congressman cycled through numerous treasurers in recent months as his campaign’s finances came under scrutiny, at one point listing someone who later denied having agreed to take the role. The treasurer identified on his filings until Friday’s amendments, Andrew Olson, did not respond to a request for comment.

The change was a reminder of Santos’s growing isolation. It came as the law firm assisting the New York congressman with matters before the FEC and the House Ethics Committee dropped him as a client, according to people familiar with the situation, who spoke on the condition of anonymity because of the matter’s sensitivity. During the last election cycle, his main campaign committee paid that firm, Dickinson Wright, about $40,000 for consulting and compliance services, according to filings.

A Dickinson Wright spokesperson did not immediately respond to a request for comment. Santos did not respond to a text message seeking comment. The congressman’s communications director resigned this week.

People familiar with the situation said they were unsure how Santos would handle matters before the FEC or House Ethics without counsel. He has a separate attorney representing him in the federal criminal case in the Eastern District of New York, who also did not respond to a request for comment.

Wide-ranging complaints filed by watchdog groups with the FEC earlier this year accused Santos of misrepresenting campaign spending and using campaign resources to cover personal expenses, among other allegations. In January, the Justice Department’s Public Integrity Section asked the FEC to hold off on any enforcement action against Santos, suggesting that prosecutors were examining overlapping issues.

Last week’s indictment accused Santos of misappropriating donor money for his personal gain and lying on personal financial disclosure forms submitted to Congress, among other alleged misdeeds. Inconsistencies with his campaign’s filings to the FEC did not figure in the charges, though legal experts said prosecutors could level additional allegations as the case proceeds.

Meanwhile, FEC analysts have continued to inquire with his various committees about errors and oversights in filings. Answering those requests will now fall to Santos as treasurer.