Washington( CNN) US District Judge Emmet Sullivan, who will oversee the sentencing of former national security consultant Michael Flynn, Thursday weighed the possibility that special counseling Robert Muller's office has been leaking grand jury secrets to the media.

The right-leaning open government group Freedom Watch is asking special courts to speed up a public records request it built in January for all communication between media outlets and the FBI, the Justice Department and its office of special counsel about the Russia probe.

Freedom Watch's lawyer Larry Klayman said he believes the records may uncover leaks to journalists that came from Robert Mueller's office.