According to an official from Hillary Clinton’s campaign, the presidential hopeful and her family personally paid a State Department staffer to maintain the private e-mail server she used while heading the agency.

The arrangement helped Hillary Clinton retain personal control over the system that she used for her public and private duties and that has emerged as an issue for her campaign, the Washington Post reported.

However, according to the campaign official, it also ensured that taxpayer dollars were not spent on a private server that was shared by Hillary Clinton, her husband and their daughter as well as aides to the former president.

That State Department staffer, Bryan Pagliano, told a congressional committee this week that he would invoke his Fifth Amendment rights against self-incrimination instead of testifying about the setup.

The private employment of Bryan Pagliano provides a new example of the ways that Hillary Clinton — who occupied a unique role as a Cabinet secretary who was also a former and potentially future presidential candidate — hired staff to work simultaneously for her in public and private capacities.

Cheryl Mills, Hillary Clinton’s chief of staff, and Huma Abedin, a close confidant who served as deputy chief of staff, both spent time working for the State Department, the Clinton Foundation or the Clintons personally.

Bryan Pagliano had served as the IT director of Hillary Clinton’s 2008 presidential campaign and then worked for her political action committee.

The Clintons paid Bryan Pagliano $5,000 for “computer services” prior to his joining the State Department, according to a financial disclosure form he filed in April 2009.

Even after arriving at the State Department in May 2009, Bryan Pagliano continued to be paid by the Clintons to maintain the server, which was in their Chappaqua, New York, home, according to the campaign official and another person familiar with the arrangement, the Washington Post reported.

The private pay arrangement has not previously been reported. The State Department has declined to answer questions about whether the private system was widely known within the agency or officially approved.

Asked in early August about whether Bryan Pagliano had been paid privately to maintain the server, a State Department official said that the agency had “found no evidence that he ever informed the department that he had outside income”.

This week, a different State Department official said he could not clarify Bryan Pagliano’s pay situation, citing “ongoing reviews and investigations” of Hillary Clinton’s e-mail setup.

Bryan Pagliano did not list the outside income in the required personal financial disclosures he filed each year.

The State Department has said Bryan Pagliano concluded his full-time service in February 2013, which coincides with Hillary Clinton’s departure as secretary.

Bryan Pagliano remains a State Department contractor doing work on “mobile and remote computing functions,” according to a State Department spokesman.