Sen. Charles Grassley, chairman of the Senate Judiciary Committee, raised questions Monday about why a top aide to Hillary Clinton was permitted to hold a special employment waiver far longer than federal law permits.

Huma Abedin, a longtime Clinton confidante, served as a full-time State Department staffer from the time Clinton entered office in January 2009 until June 2012, when she was granted a "special government employee" designation that allowed her to start collecting paychecks from the Clinton Foundation and a controversial consulting firm called Teneo Strategies while retaining her government position.

Special government employees are not permitted to hold their dual roles in the public and private sectors for longer than 130 days, Grassley noted, but Abedin worked for the Clinton Foundation, the State Department and Teneo for as many as 245 days.

"It's a problem when special government employees serve longer than the law provides," the Iowa Republican said. "Congress specified a time restriction for a reason. Special government employees are supposed to temporarily offer specialized expertise that the taxpayers can't get anywhere else.

"The time restriction makes clear that they're not supposed to be paid indefinitely while working for the private sector at the same time," he added.

Grassley began pressing the administration for the details of Abedin's employment arrangement in 2013, requesting the Government Accountability Office review of special government employee designations that were made public Monday.

The watchdog discovered the State Department had failed to report 14 special government employees to the Office of Government Ethics in 2012, the year Abedin was granted her status.

State was among three federal agencies that encountered "challenges" in handling special government employees due to "weak coordination and misunderstandings" about how the law should be applied.

Special government employees were "typically used for short-term needs and often in response to unforeseen events such as natural disasters, terrorist attacks, a resignation or an increase of work on issues requiring specific scientific expertise," according to the report.

But Abedin's case bore few similarities to the situations described as typical by the Government Accountability Office.

The Clinton aide seemingly performed her State Department duties, which included managing the secretary of state's schedule, without interruption when she received the personnel status that allowed her to take a job at the Clinton Foundation.

Abedin also joined the payroll of Teneo, a firm founded by another Clinton insider and foundation alum, Douglas Band.

Band's work with the State Department came under fire last week when previously undisclosed emails from Abedin's inbox revealed that he had pushed Clinton's staff to accommodate the requests of foundation donors.

The State Department inspector general has probed allegations that Abedin "delivered favors" for friends through her overlapping positions in the final months of Clinton's diplomatic tenure.

For example, Clinton traveled to Ireland with Abedin at her side for her last official trip as secretary, during which she attended an event hosted by a major Clinton Foundation donor that had been promoted by Teneo.

Documents published last year indicated Clinton herself signed off on the special government employee designation when it was bestowed upon Abedin in 2012.

The arrangement has repeatedly raised questions about whether Abedin's status created complex conflicts of interest for Clinton's office.

Officials covered under the personnel rules enjoy "substantially narrower restrictions than other employees on their outside representational activities," a reality that allowed Abedin to skirt the ethics laws that prevent other government employees from collecting third-party paychecks while working for the administration.

"[A] regular employee cannot receive compensation from anyone (other than the government) for performing government service," the Government Accountability Office report noted.