Rep. Cori Bush under DOJ investigation over campaign spending on security, denies wrongdoing

Missouri Democratic Rep. Cori Bush is being investigated by the Department of Justice amid allegations she misused federal funds, according to three sources familiar with the probe -- which she said was connected to her campaign's security expenditures.

In a statement issued on Tuesday, after news first broke of the investigation, Bush denied wrongdoing and said, in part: "I hold myself, my campaign, and my position to the highest levels of integrity."

"I also believe in transparency which is why I can confirm that the Department of Justice is reviewing my campaign’s spending on security services," she said.

"We are fully cooperating in this investigation, and I would like to take this opportunity to outline the facts and the truth," she continued.

She noted that "the Federal Election Commission and the House Committee on Ethics are currently reviewing the matter" as well.

Bush said that her husband had been "retained ... as part of my security team to provide security services because he has had extensive experience in this area, and is able to provide the necessary services at or below a fair market rate."

"I have not used any federal tax dollars for personal security services. Any reporting that I have used federal funds for personal security is simply false," she said, adding, "I have complied with all applicable laws and House rules–and will continue to prioritize the rules that govern us as federal elected officials."

ABC News previously reported that, according to sources familiar with the matter, the DOJ was looking at a Democrat in the House of Representatives for allegedly misusing government funds for personal security.

The DOJ has issued a grand jury subpoena to the House sergeant-at-arms for documents.

"This is to notify you formally pursuant to rule 8 of the rules of the House of Representatives that the office of the sergeant-at-arms for the House of Representatives has been served with a grand jury subpoena for documents issued by the U.S. Department of Justice," the clerk announced on the House floor earlier Monday.

Punchbowl News first reported the subpoena was related to allegations involving a House Democrat using government funds related to personal security.

The Department of Justice has declined to comment.

Representatives for the office of the House sergeant-at-arms have not responded to ABC's inquiries. Speaker Mike Johnson did not answer questions from reporters on Monday regarding the matter.

Alex Mallin and John Parkinson contributed to this report.