Independent presidential candidate Robert F Kennedy Jr is facing questions from the Federal Election Commission for payments his campaign made to his daughter-in-law last year, according to a letter from the agency.
The letter was first obtained by CNBC.
The FEC sent the letter for Mr Kennedy's campaign on Tuesday, asking for information regarding the "payments to members of the candidate's family" that were reportedly made between 1 July and 30 September.
The agency has threatened legal action against Mr Kennedy's campaign if the payments are not congruent to the fair market value of legitimate campaign services.
“If a family member is providing bona fide services to the campaign, any salary payment in excess of the fair market value of the services provided is personal use,” the FEC said in the letter.
The Independent has reached out to Mr Kennedy's campaign for comment.
The letter does not name the family member, but campaign finance records show that Mr Kennedy's daughter-in-law, Amaryllis Fox Kennedy, is the only relative his campaign has paid during the period cited by the FEC. Ms Fox Kennedy replaced former Congressman Dennis Kucinich as Mr Kennedy's campaign manager in October.
In June, before she took on the campaign manager role, Ms Fox Kennedy was paid $21,626 by the campaign for "administrative" services, according to financial disclosures, the Washington Examiner reports.
As of August, she was the highest salaried employee on Mr Kennedy's staff. She has no prior experience in campaign management and had never worked in any salaried position on any previous campaign.
Between June and September, the campaign reported paying Ms Fox Kennedy approximately $70,000.
“Salary payments made to members of the candidate’s family constitute personal use of campaign funds unless the family member is providing bona fide services to the campaign,” the FEC said in the letter, according to CNBC.
Mr Kennedy launched his campaign as a Democratic alternative to Joe Biden, but decided in October that he would instead run as an independent.
The FEC has given the Kennedy campaign a deadline of 13 February to respond.