House Republicans are pushing back against a new Democratic-led probe into an alleged plot by White House officials to share nuclear-power technology with Saudi Arabia, saying it amounts to a defamatory "conspiracy theory" and warning of consequences.

Democrats on the House Oversight Committee opened the investigation on Tuesday amid claims by several unnamed whistleblowers who said they witnessed "abnormal acts" in the White House regarding a proposal to build dozens of nuclear reactors across the Middle Eastern kingdom.

According to an interim congressional report citing whistleblowers within the Trump administration, the nuclear effort was pushed by former national security adviser Michael Flynn, who was fired in early 2017 for lying to Vice President Mike Pence and FBI agents. Derek Harvey, a National Security Council official brought in by Flynn, purportedly continued work on the proposal.

Now, congressional Republican officials are warning that Democrats -- including Maryland Rep. Elijah Cummings, the chairman of the House oversight panel -- could face ethics referrals.

“The attack on Mr. Harvey is a ridiculous conspiracy theory floated by media partisans and now, shamefully, championed by Democrats in Congress," House Permanent Select Committee on Intelligence communications director Jack Langer told Fox News. "Members of Congress who defame staff members for political purposes will be reported to the Ethics Committee.”

Lawmakers from both parties have expressed concerns that Saudi Arabia could develop nuclear weapons if the U.S. technology is transferred without proper safeguards.

FATEFUL CALL: ONETIME FBI DEPUTY DIRECTOR REVEALS THE 'ONE THING' THAT STOOD OUT TO HIM ABOUT CONVERSATION WITH FLYNN

The congressional report comes as Trump has made the Saudi kingdom a centerpiece of his foreign policy in the Middle East. This, as he tries to further isolate Iran, which is backing rebels against Saudi Arabia in a deadly proxy war in Yemen. In the process, Trump has brushed off criticism over the killing of Washington Post columnist Jamal Khashoggi and the Saudis' role in the war in Yemen.

At the same time, Trump son-in-law and senior adviser Jared Kushner is developing a Middle East peace plan that could include economic proposals for Saudi Arabia.

The White House did not immediately respond to a request for comment on the congressional report.

Relying on the whistleblower accounts, email communications and other documents, the committee's report details how National Security Council (NSC) and ethics officials supposedly warned that the actions of Flynn and a senior aide could run afoul of federal conflict-of-interest law and statutes governing the transfer of nuclear tech to foreign powers.

Flynn is awaiting sentencing for lying to the FBI in the ongoing probe of Russian meddling in the 2016 elections.

A status conference is set in his case for Mar. 13.

On Tuesday, a person close to Flynn's legal team told The Associated Press that Special Counsel Robert Mueller's team has reviewed the matters raised in the congressional report, and that no charges related to it have been filed. The person spoke on condition of anonymity, for lack of authorization to publicly discuss the ongoing investigation.

Congressional investigators are also probing the role of Tom Barrack, a proponent of the nuclear proposal who ran Trump's presidential inaugural committee, which is under separate investigation by federal prosecutors in New York. Rick Gates, a former Barrack employee and cooperator in Mueller's investigation, was also involved in advocating for the nuclear proposal.

A spokesman for Barrack said in a statement that he will cooperate with the House probe.

"Mr. Barrack's engagement in investment and business development throughout the Middle East for the purpose of better aligned Middle East and U.S. objectives are well known, as are his more than four decades of respected relationships throughout the region," the statement said, noting that Barrack never joined the Trump administration.

Harvey did not immediately return a request for comment.

According to the congressional report, the whistleblowers came to the committee because they had concerns "about efforts inside the White House to rush the transfer of highly sensitive U.S. nuclear technology to Saudi Arabia in potential violation of the Atomic Energy Act and without review by Congress as required by law — efforts that may be ongoing to this day."

A 2017 article by the nonprofit news outlet ProPublica detailed some of the concerns raised inside the National Security Council about the nuclear proposal — known as the "Marshall Plan for the Middle East" — advocated by a company called IP3 International.

DEM REP CALLS TRUMP SAUDI ARABIA'S 'B----'

IP3 is led by a group of retired U.S. military officers and national security officials, including retired Rear Adm. Michael Hewitt, retired Army Gen. Jack Keane and former Reagan National Security Adviser Bud McFarlane.

IP3 and other proponents of nuclear power in the Middle East argue that the U.S. needs to be involved because otherwise it will lose out to Russia, China and others on billions of dollars in business. They also say that U.S. involvement — and the limits on nuclear fuel that come with it— are essential to stem an arms race in the region.

"The only way to address concerns over development of weapons of mass destruction is for the U.S. to participate in the introduction and secure operation of international nuclear power plants," the company said in a statement Tuesday. It also said it "looks forward to sharing what we know" with the House committee.

Up until the month before he joined the Trump administration, Flynn listed himself on public documents as an adviser to an iteration of Hewitt's company advocating for the nuclear power proposal.

Last year, IP3 told The Washington Post that Flynn was offered a role in the company but never formally came aboard. On Tuesday, the company said Flynn "was never an advisor to IP3 or its affiliate, he had no stake in the company and was never compensated or reimbursed for expenses by IP3."

Still, according to the report, Flynn served as a conduit for IP3 inside the White House.

Just days after Trump's inauguration, the company sent Flynn a draft memo for the president's signature that would have appointed Barrack as a "special representative" in charge of carrying out the nuclear power proposal and called on the director of the CIA and the secretaries of State, Energy, Treasury and Defense to lend him support. The report also quotes former Deputy National Security Adviser K.T. McFarland as saying Trump personally told Barrack he could lead the plan's implementation.

The report also catalogs the actions of Harvey, the Flynn confidant who was put in charge of the NSC's Middle East and North African affairs.

CLICK TO GET THE FOX NEWS APP

According to the report, upon entering the White House in January 2017, Harvey saw his mission as getting Trump to adopt the nuclear proposal despite the objections of ethics and national security officials.

Even when H.R. McMaster, who replaced Flynn as national security adviser, and NSC lawyer John Eisenberg directed that work stop on the proposal because of concerns about its legality, Harvey continued pursuing the proposal, according to the report.

Harvey was fired from the NSC in July 2017. He then joined the staff of GOP Rep. Devin Nunes of California, a Trump ally and the former hairman of the House intelligence committee.

Fox News' Catherine Herridge and The Associated Press contributed to this report.