Republican U.S. Senate candidate Herschel Walker gives a concession speech during his election night party after losing the U.S. midterm runoff election to Democratic U.S. Senator Raphael Warnock (D-GA) in Atlanta, Georgia, U.S., December 6, 2022. (REUTERS/Alyssa Pointer)

(CNN) — A watchdog group is asking federal election regulators to investigate whether Republican Herschel Walker violated campaign finance laws during his unsuccessful 2022 US Senate bid in Georgia.

The complaint, filed Friday with the Federal Election Commission by Citizens for Responsibility and Ethics in Washington, or CREW, includes emails published earlier this week by The Daily Beast that appear to show Walker soliciting a large donation for his campaign from Montana billionaire Dennis Washington and then directing Washington’s representative to send more than $530,000 of the total to Walker’s personal company, HR Talent.

Federal law restricts the size of donations that individuals can contribute directly to a candidate’s campaign, and candidates are prohibited from soliciting donations that exceed those limits.

The complaint alleges that the emails show that Walker solicited contributions “far in excess” of the limits and asks the commission to investigate, “impose sanctions appropriate to these violations, and take such further action as may be appropriate, including referring this matter to the Department of Justice for criminal prosecution.”

CNN’s repeated attempts to reach Walker on Friday were unsuccessful. The Daily Beast has said that Walker did not respond to requests for comment on its reporting.

Walker lost his Senate bid to Democratic incumbent Raphael Warnock in a December runoff.

In a statement, Jon Bennion, a spokeperson for Washington, confirmed that a “certain portion” of the family’s political contributions went to a “non-political account.” Once discovered, he wrote, “the Washingtons immediately requested and received a full refund of such funds.”

Bennion said Washington’s team would have no further comment on the matter.

In its complaint, CREW argues that soliciting excess campaign contributions — even if later refunded — still amounts to a violation of federal regulations.

“The evidence we’ve seen so far raises so many questions about what was really going on here that only an immediate and thorough investigation will suffice,” the group’s president, Noah Bookbinder, said in a statement.

Citing agency policy, officials in the FEC press office said Friday they could not confirm whether the commission had received the complaint or otherwise comment on it.