A federal district court judge detailed Wednesday how a legal watchdog group can dig into the creation and operation of Hillary Clinton’s private email system — and didn’t rule out a deposition of the former secretary of state and current Democratic presidential front-runner.  

U.S. District Judge Emmet G. Sullivan issued an order Wednesday detailing discovery in Judicial Watch’s lawsuit seeking records about Clinton and her top advisers, including the private email system she used during her four-year tenure as secretary of state.  

Clinton’s use of a private server for email also has spurred a Justice Department investigation and has become a key point of election-year criticism from Republicans. In the court case, Sullivan said that more information is needed for him to decide whether the State Department adequately searched relevant records in response to Judicial Watch’s Freedom of Information Act request.  

“In sum, the circumstances surrounding approval of Mrs. Clinton’s use of clintonemail.com for official government business, as well as the manner in which it was operated, are issues that need to be explored” before he can rule, the order states.  

[Related: Obama Steadfast on Court Pick, Defends Clinton on Emails]

The order allows Judicial Watch, a conservative group, to take depositions from State Department employees as well as Cheryl Mills, Clinton’s former chief of staff, and Huma Abedin, Clinton’s former deputy chief of staff and senior adviser who had an email account on the server, clintonemail.com.  

It also leaves open the possibility that Judicial Watch could take a deposition from Clinton herself.  

“Based on information learned during discovery, the deposition of Mrs. Clinton may be necessary,” the order states. “If plaintiff believes Mrs. Clinton’s testimony is required, it will request permission from the court at the appropriate time.”  

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