DENVER (KDVR) — U.S. Rep. Lauren Boebert is facing an investigation over some of her campaign reimbursements after a political action committee filed a complaint.

American Muckrakers, a PAC that’s gone after conservative members of Congress, reportedly filed a complaint with the Colorado Attorney General’s Office about Boebert’s mileage reimbursements.

“The Department of Law received an investigation request,” said Lawrence Pacheco, spokesperson for the AG’s Office. “We referred it to the appropriate agencies to evaluate the allegations and whether any legal actions are justified, which is standard practice.”

Boebert called it “a swing and a miss from a partisan political group” and stands by the mileage charges.

Boebert’s mileage reimbursements raised alarm among ethics experts in early 2021. Federal Election Commission filings showed her campaign reimbursed her for more than $21,000 for mileage between April and Nov. 11, 2020.

Candidates use the IRS mileage rate, which is 57.5 cents per mile. That means Boebert drove 36,869 miles in about seven months.

Boebert later updated and itemized the filings, logging that some of the money was instead spent on things like Uber rides and hotel stays.