(CNN) Special counsel Robert Mueller's office is still working with former national security adviser Michael Flynn, according to a status report before his sentencing Friday.

"Due to the status of the Special Counsel's investigation, the parties do not believe this matter is ready to be scheduled at this time," the filing said.

They asked for another two months before they must update the court again.

This is the third time the lawyers asked to delay Flynn's sentencing. Flynn pleaded guilty to lying to investigators in December and is cooperating with the investigation into Russian interference in the election. He has not been sentenced.

Sentencing delays like these could signal the expectations prosecutors have about the length of their investigation. In short, the request regarding Flynn on Friday suggests the former national security adviser wouldn't be sentenced before the fall and is still of use to investigators.

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