The House Oversight Committee and the Treasury Department have launched simultaneous investigations into Governor Tim Walz’s administration in Minnesota, citing its alleged role in a massive fraud scheme that officials say cost taxpayers more than $1 billion.

The probes center on “Feeding Our Future,” a COVID-era food relief program that federal prosecutors say was exploited by fraudsters — largely Somali immigrants — to purchase luxury cars and real estate. New allegations suggest some of these funds may have been funneled to the Somali terrorist organization al-Shabab.

The House Oversight Committee chairman, James Comer of Kentucky, confirmed the investigation to The New York Post, saying his panel “will conduct a thorough investigation into Governor Walz’s failure to safeguard taxpayer dollars.”

“Minnesota Governor Tim Walz was warned about massive fraud in a pandemic food-aid program for children, yet he failed to act. Instead, whistleblowers who raised concerns faced retaliation,” Mr. Comer said.

Mr. Walz defended his record on NBC’s “Meet the Press,” saying he took “responsibility for putting people in jail” connected to the fraud, while distinguishing his administration’s issues from Mr. Trump’s legal challenges.

“My God, there’s a big difference between fraud and corruption. And corruption is something he knows about,” Mr. Walz said of the president. “Donald Trump: Deflect, demonize, come up with no solutions. He’s not going to help fix anything on fraud.”

The exchange devolved into personal insults over the holiday weekend. In a Thanksgiving message, Mr. Trump attacked Mr. Walz’s intellectual capacity, calling him “seriously retarded.”

The president has also described Minnesota as effectively “a hub of fraudulent money laundering activity” and ordered a review of green cards issued to migrants from Somalia and other nations.

As the investigation proceeds, Mr. Comer’s committee holds the power to issue subpoenas and refer alleged crimes to the Department of Justice for further prosecution.

Simultaneously, Treasury Secretary Scott Bessent announced via X that he has instructed investigators to examine how “the feckless mismanagement of the Biden Administration and Governor Tim Walz” potentially allowed tax dollars to reach terrorist groups.

“We are acting fast to ensure Americans’ taxes are not funding acts of global terror. We will share our findings as our investigation continues,” he wrote on X.

While the Department of Justice has already successfully prosecuted 59 people in connection with the scheme, the new investigations aim to determine the extent of state-level negligence. Prosecutors allege that between April 2020 and January 2022, funds from the Minnesota Department of Human Services and Department of Education were diverted to the nonprofit Feeding Our Future and other organizations.

Instead of feeding children, prosecutors say the “depraved and brazen” plot funded lavish lifestyles for the nonprofit’s workers. The FBI raided the organization in January 2022, leading to its dissolution.

A June 2024 audit by the Minnesota Office of the Legislative Auditor found that the state Department of Education had “created opportunities for fraud” and maintained “inadequate oversight” during the two-year period.

A whistleblower account on X, claiming to represent nearly 500 employees of the Minnesota Department of Human Services, publicly criticized Mr. Walz over the weekend.

“We let Tim Walz know of fraud early on, hoping for a partnership in stopping fraud but no, we got the opposite response,” the account posted on Saturday. “Tim Walz systematically retaliated against whistleblowers using monitoring, threats, repression, and did his best to discredit fraud reports. Instead of partnership, we got the full weight of retaliation.”

The group characterized the environment as “scary, isolating and left us wondering who we can turn to.”

Mr. Walz, who is seeking a third term, has previously said he was aware of suspicious activity as early as November 2020. While the Department of Education initially moved to stop payments to the nonprofit, they resumed after Feeding Our Future sued, alleging racial discrimination.

Mr. Walz has claimed a Minnesota judge ordered the payments to continue. However, Ramsey County District Judge John Guthmann issued a statement denying this, clarifying that payments were “made voluntarily” by the department after the nonprofit claimed to have resolved deficiencies.