A federal judge has ordered the State Department to ask Democratic presidential candidate Hillary Clinton to certify under penalty of perjury that she has turned over some of the work-related emails she kept on a private server during the four years she served as secretary of state.

U.S. District Court Judge Emmet Sullivan issued the order Friday in connection with a Freedom of Information Act lawsuit the conservative group Judicial Watch filed in 2013 seeking records about the employment status of Clinton aide Huma Abedin, who worked as Clinton’s deputy chief of staff but later transferred to a part-time job as a so-called “special government employee.”

The State Department told Judicial Watch last year that all records about the arrangement had been disclosed, but after Clinton’s use of a private email account for official business was revealed earlier this year, Judicial Watch moved to reopen the lawsuit. Abedin was also revealed to have used an account on the same server.