When President Donald Trump nominated Alexander Acosta for Secretary of Labor in February 2017, he had an immediate backer in Sen. Marco Rubio.

"I know Alex Acosta well, and he is a phenomenal choice to lead the Department of Labor," the Florida Republican said in a statement. "Alex has succeeded in all endeavors he has taken on, and managing the Department of Labor will be no different."

Rubio introduced Acosta at the cabinet nominee's confirmation hearing before the Senate Health, Education, Labor and Pensions Committee. During his confirmation vote, he praised Acosta as a "a brilliant legal mind."

"With every challenge he has confronted throughout his distinguished career, he has demonstrated his ability to effectively tackle the problems at hand with ease," Rubio told the Senate.

Now, a deeply reported and devastating Miami Herald investigation has shed new light on the role Acosta played in a decade-old South Florida child sex-ring case involving billionaire Jeffrey Epstein.

According to the story, Epstein was credibly accused of sexually abusing dozens of underage girls, as young as 13 to 16 years old. Police had built a strong case, documenting a scheme to lure teenage girls into Epstein's Palm Beach mansion with money to perform massages which often turned into sexual content.

Epstein could have gone to prison for life. But the Herald reported that Acosta, then Miami's top federal prosecutor, cut Epstein a deal that allowed the billionaire to avoid serious jail time and prevented his victims from testifying.

From the Herald:

Not only would Epstein serve just 13 months in the county jail, but the deal — called a non-prosecution agreement — essentially shut down an ongoing FBI probe into whether there were more victims and other powerful people who took part in Epstein's sex crimes, according to a Miami Herald examination of thousands of emails, court documents and FBI records.

The pact required Epstein to plead guilty to two prostitution charges in state court. Epstein and four of his accomplices named in the agreement received immunity from all federal criminal charges. But even more unusual, the deal included wording that granted immunity to "any potential co-conspirators'' who were also involved in Epstein's crimes. These accomplices or participants were not identified in the agreement, leaving it open to interpretation whether it possibly referred to other influential people who were having sex with underage girls at Epstein's various homes or on his plane.

As part of the arrangement, Acosta agreed, despite a federal law to the contrary, that the deal would be kept from the victims. As a result, the non-prosecution agreement was sealed until after it was approved by the judge, thereby averting any chance that the girls — or anyone else — might show up in court and try to derail it.

A spokeswoman for Rubio did not respond when asked Thursday if the Senator's opinion of Acosta had changed after the story.

However, Rubio on Friday told a reporter for WPLG in Miami that it would be "very troubling" if political influence led to a light sentence for Epstein but he said he will reserve judgment until he hears Acosta's side. He acknowledged, though, Acosta may not be able to say much.

"There's probably more to it than what you've seen," Rubio said. "That man should have been in jail for a long time."

Rubio added that Acosta has done a "good job" as Labor Secretary and removing him would be "disruptive."

Acosta is also rumored to be a potential replacement for the recently departed attorney general Jeff Sessions. Rubio's office didn't say whether he would support Acosta for that cabinet position.

Rubio traveled on Air Force One with Acosta last year soon after the Labor Secretary's confirmation hearing to visit Miami and unveil the administration's new Cuba policy.

Outgoing Democratic Sen. Bill Nelson also voted to confirm the Florida-native Acosta for Secretary of Labor. His office didn't respond to a request for comment either.

Acosta was questioned about the Epstein case during his Senate confirmation hearing, and said, "a plea that guarantees someone goes to jail, that guarantees he register [as a sex offender] generally and guarantees other outcomes, is a good thing." However, many of the details of the case were not known until the Herald's investigation published this week.

Asked about the Herald story, Department of Labor spokeswoman Megan Sweeney said, "This matter has been publicly addressed previously, including during confirmation hearings. The U.S. Attorney's Office for the Southern District of Florida has defended the actions in this case across three administrations, and the U.S. Attorney's Office for the Southern District of Florida is the appropriate office for your inquiry."

This story was updated Friday with Rubio's comments to WPLG.