A group of 15 Democrats urged the Justice Department's Office of the Inspector General to open up an investigation into whether Labor Secretary Alexander Acosta, while serving as U.S. attorney for Miami a decade ago, cut too favorable of a deal for a wealthy serial sex offender.

The letter concerns Acosta's handling of a 2007 case involving the investor and sex offender Jeffrey Epstein, who was convicted on two counts of prostitution in 2007 and served just over a year in county jail. A lengthy Miami Herald story last week regarding the case portrayed Acosta as giving in to pressure to cut a favorable deal for Epstein, a wealthy political donor who around the same time was a witness in federal case against a pair of Bear Stearns executives who were being charged with securities fraud.

The lawmakers note that Epstein originally faced a 53-count federal indictment for sex trafficking and related crimes. "Rather than pursue the indictment fully to ensure that the individual could never again prey on minor girls, Secretary Acosta entered into an extremely preferential deal that resulted in this perpetrator of horrific crimes against children serving just 13 months in county jail," they wrote. The lawmakers noted that the plea deal also shut down an FBI investigation into whether there were more victims.

The letter was written by Rep. Debbie Wasserman Schultz, D-Fla., and signed by 14 other Democrats. It was dated Friday but only sent Monday, having been circulated over the weekend to get additional lawmaker signatures, Wasserman Schultz's office said. It was directed to the OIG's office because Acosta was a Justice Department official at the time he cut the deal.

The lawmakers point to no indication that Acosta himself committed a violation in striking the deal but nevertheless called for a probe into the "circumstances surrounding the non-prosecution agreement," noting that several documents and case files remain redacted.

A spokesman of the OIG's office could not be reached for comment.

"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," a DOL spokesman told the Washington Examiner.