The Internal Revenue Service issued a rare apology to billionaire investor Ken Griffin over the leak of his tax returns to the press.

The apology follows the Monday settlement of a lawsuit the Citadel CEO filed against the IRS in 2022, alleging that an employee at the agency illegally leaked his tax returns to the news site ProPublica.

In 2021, ProPublica also published other billionaires’ tax information, including Tesla CEO Elon Musk, Amazon founder Jeff Bezos and real estate mogul Stephen Ross, in a 2021 series called “The Secret IRS Files.”

The IRS employee in question — government contractor Charles Littlejohn — also leaked the confidential tax returns of thousands of other wealthy Americans to the New York Times.

The former government contractor was sentenced to five years in prison in January after he pleaded guilty to unauthorized disclosure of tax returns.

“The IRS takes its responsibilities seriously and acknowledges that it failed to prevent Mr. Littlejohns criminal conduct and unlawful disclosure of Mr. Griffins confidential data,” the IRS said in a statement.

“Accordingly, the IRS assures Mr. Griffin and the other victims of Mr. Littlejohns actions that it has made substantial investments in its data security to strengthen its safeguarding of taxpayer information.”

Littlejohn accessed the tax data through an IRS database and uploaded it to a private website to avoid the agency barrier preventing large downloads. He passed former president Donald Trump’s tax information to the New York Times and passed others’ information, including Griffin’s, to ProPublica.

“He violated the terms of his contract and betrayed the trust that the American people place in the IRS to safeguard their sensitive information,” the IRS said in a statement.

The billionaire’s lawyer, William A. Burck of Quinn Emanuel Urquhart & Sullivan, LLP, said the lawsuit came after years of stonewalling.

“Although the IRS has acknowledged its failures, apologized to the thousands of Americans who were victimized, and has promised to protect taxpayer information in the future, it is important that all of us hold it accountable to satisfy that promise,” Burck told the Post in a statement. 

“I am grateful to my team for securing an outcome that will better protect American taxpayers and that will ultimately benefit all Americans,” Griffin said in a statement to multiple news outlets, including CBS and FOX, Tuesday.