Vice President JD Vance has referred Minnesota Gov. Tim Walz and state Attorney General Keith Ellison to the Justice Department for a criminal fraud investigation involving social services programs.

"Minnesota state officials are not above the law, and if they facilitated fraud, lied under oath about what they knew, or harassed and intimidated whistleblowers, they must face justice," Vance wrote on X Monday. 

Vance said the referral was prompted by a letter and report from the Republican-led House Oversight Committee, reports NBC News.

The report accused Walz's administration of failing to stop fraud in taxpayer-funded social service programs and of retaliating against state employees who voiced concerns about misusing government funds. 

Oversight's report concluded that Minnesota state leaders were aware of fraud concerns for years but failed to take available steps to halt payments or remove questionable providers from government programs.

The House Oversight Committee on Sunday sent a letter to Vance urging him, in his role as head of the White House's Task Force to Eliminate Fraud, to review Minnesota's social services programs.

President Donald Trump appointed Vance to lead the task force in February after announcing a "war on fraud" during his State of the Union address.

Shortly afterward, Vance and Centers for Medicare & Medicaid Services Administrator Mehmet Oz announced a pause in federal Medicaid reimbursements to Minnesota.

Walz rejected the move at the time, saying it had "nothing to do with fraud" and describing it as a "campaign of retribution."

"Trump is weaponizing the entirety of the federal government to punish blue states like Minnesota," Walz wrote on X on Feb. 25.

Minnesota has faced increased federal scrutiny during Trump's second term over allegations of fraud involving daycare centers and social service programs.

State officials said in January that childcare facilities at the center of some allegations were not operating improperly.

Federal law enforcement agencies conducted a series of raids in April as part of an investigation into alleged welfare fraud.

The Department of Homeland Security said at the time that the searches were carried out under warrants related to "the rampant fraud of American taxpayer dollars."

Trump and his allies have claimed members of Minnesota's Somali community were involved in the alleged fraud.

Walz praised the April raids, saying they were conducted in coordination with Minnesota authorities after state agencies identified and reported suspicious activity.

"That's how the system is supposed to work, and our agencies will keep at it as long as there are fraudsters around to put behind bars," Walz wrote on X.

The referral marks the latest Justice Department scrutiny involving Walz or the state of Minnesota under the Trump administration.

In January, the Justice Department opened an investigation into Walz and Minneapolis Mayor Jacob Frey, alleging they conspired to impede federal immigration enforcement through public statements.

The investigation followed a large federal immigration operation in Minneapolis that sparked protests and resulted in the deaths of Renee Good and Alex Pretti.

Walz has described that investigation as politically motivated.

Last month, the DOJ filed another complaint against Minnesota over its regulation of global greenhouse gas emissions. 

In addition, federal criminal charges were filed last month in Minnesota against 15 individuals allegedly involved in what officials described as the largest Medicaid autism fraud case ever brought by the Department of Justice, which claims $90 million was stolen from the program.