FBI special counsel Robert Mueller on Thursday filed a request for 70 blank subpoenas in the Virginia court presiding over one of two criminal proceedings involving former Trump campaign chairman Paul Manafort.

The two-page filing does not reveal any details.

However, Courthouse News Service noted each subpoena orders the recipient to appear at the federal courthouse in Alexandria, Virginia, on July 10 at 10 a.m. ET to testify at Manafort's trial on charges stemming from Mueller's probe of Russian meddling in the 2016 presidential election.

The Washington Examiner noted the 70 blank subpoenas amount to 35 total possible subpoenas — in each case, a subpoena is needed for the witness and another is needed for the defense. Court documents filed last month show Mueller's team was pushing to subpoena 35 witnesses in the trial, the Examiner reported.

Manafort faces no charges related to the Trump campaign, but he is accused in cases filed both in Alexandria, and Washington, D.C., of hiding the work he did for and the money he made from a Russia-friendly political party in Ukraine and former Ukrainian president Viktor Yanukovych.

In Virginia, he is also accused of concealing foreign bank accounts, falsifying his income taxes and failing to report foreign bank accounts.

In Washington, Manafort faces counts of conspiracy to launder more than $30 million, making false statements, failing to follow lobbying disclosure laws and working as an unregistered foreign agent.

The subpoena request comes one day before Manafort — who has pleaded not guilty in both cases — is expected to appear in a Virginia federal court where his attorney, Kevin Downing, will make a case for dropping of several counts against his client, CNS reported.

According to CNS, a Monday night filing shows Downing requested a hearing to air his concerns Manafort's chances at a fair trial have been spoiled because of media reports featuring leaks from anonymous government officials.

News of the subpoenas in the Virginia case comes on the same day of the revelation that federal investigators kept logs of the phone lines of President Donald Trump's personal lawyer Michael Cohen.

NBC News corrected an earlier story that said the lines were wiretapped to allow investigators to hear the calls.

"In this case, they were just able to see that somebody called somebody else," but they were not able to listen to the calls, NBC News reporter Tom Winter, one of the two reporters bylined on the story, said on MSNBC.

NBC News reported the monitoring of Cohen's phone lines was in place before the FBI seized records and documents in an April 9 raid on his offices, hotel room, and home.