Virginia Gov. Terry McAuliffe (D) said Tuesday that he is “very confident” that the FBI will find no wrongdoing in its investigation of donations to his 2013 campaign and his personal finances. (Win Mcnamee/Getty Images)

The surprise news of an FBI inquiry into Virginia Gov. Terry McAuliffe has uncomfortable parallels to an FBI security review of his friend and political patron Hillary Clinton’s email system, but Clinton allies said it is unlikely to do her lasting harm.

McAuliffe (D) said Tuesday that he is “very confident” that the FBI will find no wrongdoing in its investigation of donations to his 2013 campaign and his personal finances. He said his reaction to news of the probe, which may have been underway for a year, was “shock.”

McAuliffe has many things in common with Bill and Hillary Clinton, his political benefactors and close friends. Along with overlapping business, political and social spheres, he shares their history of prodigious Democratic fundraising and financial dealings that have drawn scrutiny.

And now he shares the unwelcome news that the FBI is looking into the propriety of decisions or actions taken in his name.

“When you put the word FBI with anything or anyone, the optics aren’t good,” joked John Morgan, a longtime friend and donor to both Clinton and McAuliffe.

Clinton friends and supporters said they are concerned for McAuliffe but not, at this point, for Clinton.

“I don’t think it has anything to do with Hillary Clinton,” McAuliffe said Tuesday, adding that the inquiry also would not hamper his effectiveness as governor.

“If you haven’t done anything wrong, then you have nothing to worry about,” he told reporters.

The three-decade friendship between McAuliffe and the Clintons has been marked by favors done and received on both sides. McAuliffe is in a position this year to bestow a big one — delivering a key swing state for Hillary Clinton in the presidential race.

What little is known about the FBI investigation into McAuliffe has a familiar ring, with parallels to criticism of Clinton fundraising during Bill Clinton’s presidency and afterward, through the Clinton Foundation.

Neither the foundation nor the presidential campaign is a target of the probe, an official told The Washington Post on Monday. The official spoke on the condition of anonymity because he was not authorized to publicly discuss the ongoing investigation.

CNN first reported the inquiry, saying that investigators are looking into a six-figure contribution that Chinese businessman Wang Wenliang made to McAuliffe’s campaign through his U.S. businesses.

But a federal official told The Post that federal investigators are looking broadly at donations to McAuliffe and at his personal finances.

Attorneys for McAuliffe’s 2013 gubernatorial campaign carefully reviewed all donations, the governor said.

McAuliffe hosted a fundraiser for Clinton and state Democratic parties at his McLean home last month, and he is helping scramble donors nationwide to help her gird for a bruising general election contest with Republican Donald Trump. Both Bill and Hillary Clinton helped raise money for McAuliffe’s 2013 campaign in Virginia, a kind of graduation to elected office for a famously energetic Democratic fundraiser and operative who helped elect others.

Morgan, who hosted a big fundraising party for McAuliffe at his Florida home in 2013 and whose law firm donated $107,000 to McAuliffe the same year, said his old friend was “fastidious” about ensuring that donations to the Democratic National Committee were proper when he served as party chairman.

He predicted that the FBI inquiry would come to naught.

“On a scale of one to 10 of things to be worried about, I’m at a minus-five on this,” he said.

Other Clinton friends and political allies said there is some concern that the inquiry could drag on without resolution, inviting comparisons with the seemingly endless special prosecutor inquiries into various Clinton financial and fundraising operations. Hillary Clinton has dismissed many of those as evidence of Republican political skullduggery.

The McAuliffe probe is being run by a different part of the FBI from the inquiry into whether government secrets were compromised by the private email system Clinton used for her government work at the State Department. She has said she never intentionally sent or received classified information and has predicted the inquiry will show no wrongdoing.

Both inquiries, however, introduce what one Clinton backer called the “fear of the unknown” into Clinton’s presidential run.

“Nobody wants to wake up on a Monday and find out they are the subject of an FBI investigation,” said one longtime Clinton and McAuliffe friend. “And nobody wants to have those kinds of questions close to a presidential campaign.”

Clinton did not address the McAuliffe matter in campaign remarks Tuesday, and her campaign headquarters had no immediate comment on the development.

The Republican National Committee sent reporters a list of news articles detailing the many layers of personal and professional links between McAuliffe and the Clintons, whose New York house he helped them buy as they left the White House with heavy legal debt in 2001.

“Please see a refresher on how closely linked the Virginia governor is to the Clintons and the controversial fundraising practices he stewarded in the 1990s that practically placed a ‘for sale’ sign on the White House and set a new low for ethics in government,” a RNC spokesman wrote.

The Trump campaign has concluded that the email inquiry is a lose-lose proposition for the candidate he now calls “Crooked Hillary.” Any criminal prosecution would obviously be a blow to her presidential chances. But even if she and close aides are cleared, Republicans can claim a whitewash by a Democratic attorney general.

The federal inquiry includes a period before McAuliffe was elected and when he was serving as an unpaid director for the Clinton Foundation. Wang has also donated to the foundation, giving $2 million.

Many details of the federal probe, including what prompted it, remain unclear, and one official said there is skepticism among prosecutors about whether it will lead to charges.

That official said investigators have been scrutinizing McAuliffe’s finances — including personal bank records, tax returns and public disclosure forms that date back many years — and are interested in foreign sources of income.

It may concern a $120,000 donation to McAuliffe’s gubernatorial campaign from West Legend Co., the New Jersey affiliate of Rilin Enterprises, a Chinese firm led by Wang.

Wang’s donations attracted interest because he is closely linked to the Chinese government, both as a member of the National People’s Congress and as a contractor entrusted to build China’s embassies.

Foreign nationals are prohibited under federal law from making political contributions, except immigrants who hold green cards. An American subsidiary of a foreign corporation cannot contribute campaign funds if it is financed in any way by its parent company or if individual foreign nationals are involved in the decision to make the donation.

But Wang holds U.S. permanent resident status, which makes him eligible to donate to McAuliffe’s campaign.

Jenna Portnoy in Boyce, Va., Rachel Weiner and Matt Zapotosky contributed to this report.