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

Yet Sullivan was doubtful that has happened.

The right-leaning open government group Freedom Watch is asking the court to speed up a public records request it made 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 attorney Larry Klayman said he believes the records may reveal leaks to journalists that came from Robert Mueller's office.

Klayman had asked to see all 9,000 pages of communication between the government and the media by July 9. But Sullivan, weighing both Klayman's request and the efforts of the small staff at the special counsel's office, pushed the Justice Department's deadline back to September 4. Klayman said he will make the documents public once he receives them.

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