The Department of Justice has opened an investigation into Secretary of Labor Alex Acosta’s role in negotiating a controversial plea deal with a wealthy New York investor accused of molesting more than 100 underage girls in Palm Beach.

The probe is in response to a request by Sen. Ben Sasse, a Nebraska Republican and member of the Senate Judiciary Committee, who was critical of the case following a series of stories in the Miami Herald. The Herald articles detailed how Acosta, then the U.S. attorney for Southern Florida, and other DOJ attorneys worked hand-in-hand with defense lawyers to cut a lenient plea deal with multimillionaire Jeffrey Epstein in 2008.

Acosta, 50, had been considered a rising star in the Republican Party and was once mentioned as a possible candidate to replace Attorney General Jeff Sessions. He did not respond to a request for comment emailed to his office on Wednesday.

Sasse and U.S. Rep. Debbie Wasserman Schultz, a Sunrise Democrat, have pushed for a DOJ investigation into whether there was any undue influence that tainted the case.

“Jeffrey Epstein is a child rapist and there’s not a single mom or dad in America who shouldn’t be horrified by the fact that he received a pathetically soft sentence,’’ Sasse said on Wednesday. “The victims of Epstein’s child sex trafficking ring deserve this investigation — and so do the American people and the members of law enforcement who work to put these kinds of monsters behind bars.’’

The case has raised fundamental questions about whether well-connected, wealthy people wield influence over prosecutors and others in the justice system. Epstein had a wide circle of powerful friends, including Bill Clinton, President Donald Trump, Prince Andrew, lawyer Alan Dershowitz and a former prime minister of Israel, Ehud Barak.

Michael Horowitz, the Justice Department’s inspector general, has urged Congress to allow him to conduct a probe, noting that OPR’s investigations often shield prosecutors accused of wrongdoing.

But Horowitz needs Congress to change the law to give him the power to proceed with what he called a more “independent’’ review of the case.

House Democrats launched a sweeping new Russia investigation Wednesday with the promise to dig deep into President Trump’s family and their money.

The new probe takes aim at Trump’s business, and it will investigate whether any of his administration’s decisions have been influenced by financial incentives dangled by foreign actors.

California Rep. Adam Schiff, chairman of the House Intelligence Committee, acknowledged the ongoing investigation of special counsel Robert Mueller while announcing the new congressional probe.

“[T]he Committee must fulfill its responsibility to provide the American people with a comprehensive accounting of what happened, and what the United States must do to protect itself from future interference and malign influence operations,” Schiff wrote in a statement Wednesday.

The investigation will have 5 vectors:

• Russian attempts to influence U.S. politics
• Links between Russia and Trump’s team
• “Whether any foreign actor has sought to compromise or holds leverage, financial or otherwise, over Donald Trump, his family, his business, or his associates”
• Whether Trump and his inner circle have ever been vulnerable to foreign exploitation, or tried to steer U.S. government policy to benefit foreign interests
• Whether anyone has tried to obstruct investigations, including those run by Congress

A previous Russia investigation in the House Intelligence Committee was closed by Republican leadership last March, amid partisan squabbling over whether its work was really finished. The committee’s GOP majority released a final report concluding there was no evidence Trump colluded with Russian efforts to interfere with the 2016 presidential election. Democrats in the minority published their own take, arguing that many potential leads were never followed up on.

Now, Schiff is signaling that the committee is about to take a deep look at whether Trump may be awash in dirty Russian money.