Aides to Hillary Clinton and State Department officials should be questioned under oath about Clinton’s use of a private email server during her four years as secretary of state, a federal judge ruled on Tuesday.



“There has been a constant drip, drip, drip of declarations,” said US district judge Emmet G Sullivan of Washington. “When does it stop?”

The judge did not rule out a subpoena for Clinton and top aide Huma Abedin.

The ruling, which was first reported in the Washington Post, advances an investigation into whether Clinton or others had acted in violation of the Freedom of Information Act.

Clinton seems on track to win the Democratic presidential nomination, with victories in two of three states to have voted so far and a rosy outlook for the contests ahead.

But the emails issue continues to dog her candidacy, distract advisers, and feed outrage on the right that Clinton has escaped answering for the episode and trepidation on the left that it might cripple her candidacy.

Hillary Clinton’s top aide, Huma Abedin, at a rally in New Hampshire. Photograph: Brian Snyder/Reuters

The Obama administration could appeal against Sullivan’s ruling, which arose out of a court challenge by a conservative legal watchdog, Judicial Watch. The group had requested information three years ago on the job duties of Abedin, who has variously served as a personal aide, State Department staff member and political advisor to Clinton, as well as a private consultant elsewhere.

Sullivan said the government’s handling of the emails issue created “at least a ‘reasonable suspicion’” that the government was keeping the public from appropriately accessing public records.

“This case is about the public’s right to know,” he said.