Billionaire hedge fund manager Ken Griffin has filed a lawsuit against the Internal Revenue Service alleging that someone at the agency illegally leaked his tax returns to the news site ProPublica last year.

Griffin, the founder and CEO of Citadel, accused the IRS and the Treasury Department of breaching privacy laws after ProPublica published tax information of billionaires including Tesla CEO Elon Musk, Amazon founder Jeff Bezos and real estate mogul Stephen Ross.

The Post has sought comment from the Treasury Department, which has vowed to investigate the leak.

ProPublica published a series of exposes titled “The Secret IRS Files” last year examining thousands of tax returns belonging to the wealthiest Americans.

The site reported that between 2013 and 2018, Griffin, whose net worth is estimated by Forbes to be $31.9 billion, reported an average annual income of almost $1.7 billion, but paid a tax rate of just 29.2% — far lower than the top marginal income tax rate of nearly 40%.

ProPublica found that other moguls worth billions managed to avoid income tax entirely for years by claiming substantial losses in their businesses.

“The IRS made these unlawful disclosures knowingly, or at the very least negligently or with gross negligence,” Griffin’s lawsuit, which was filed in Miami federal court on Tuesday, states.

“The IRS willfully failed to establish appropriate administrative, technical, and physical safeguards to insure the security and confidentiality of Mr. Griffin’s confidential taxpayer information.”

The lawsuit continued: “Despite being aware of its security deficiencies for over a decade, the IRS willfully failed to establish appropriate administrative, technical, and physical safeguards to insure the security of confidential tax return information, including Mr. Griffin’s confidential tax return information.”

“IRS personnel exploited these willful failures to misappropriate Mr. Griffin’s confidential tax return information and unlawfully disclose that information to ProPublica for further publication,” the court filing stated.

Griffin is seeking $1,000 for each act of “unauthorized” disclosure as well as unspecified damages.

Republicans, who expressed outrage at the leak of the tax returns, have vowed to pursue further investigations once they assume control of the House of Representatives after the new year.

“IRS employees deliberately stole the confidential tax returns of several hundred successful American business leaders,” Griffin said in a statement published by The Wall Street Journal.

“It is unacceptable that government officials have failed to thoroughly investigate this unlawful theft of confidential and personal information.”

Stephen Engelberg, ProPublica’s editor-in-chief, and the site’s then-president, Dick Tofel, wrote last year they were “quite selectively and carefully” publishing confidential tax return data because “we believe it serves the public interest in fundamental ways, allowing readers to see patterns that were until now hidden.”

ProPublica has not specified precisely how it obtained the information.