The Federal Election Committee sent a letter to the treasurer of Rep. Lauren Boebert (R-Colo.) inquiring about the suspected use of campaign funds for her personal expenses.

State of play: The FEC letter shows four Venmo payments totaling over $6,000 described as "personal expense of Lauren Boebert billed to campaign account in error." It is then noted that the expenses were reimbursed.

What they're saying: "If it is determined that the disbursement(s) constitutes the personal use of campaign funds, the Commission may consider taking further legal action," Shannon Ringgold, FEC senior campaign finance analyst, wrote in her letter.

• "However, prompt action to obtain reimbursement of the funds in question will be taken into consideration," Ringgold added.

The other side: "The Venmo charges were personal expenses that were billed to the campaign account in error. The reimbursement has already happened and will appear in the Q3 filing," a Boebert spokesperson told CNBC on Wednesday.

Context: The FEC prohibits the use of campaign funds for personal use.

• The commission says personal use constitutes the use of campaign funds to fulfill "a commitment, obligation or expense of any person" that is not related to the candidate's campaign or to their office responsibilities.