WASHINGTON (WASHINGTON POST) - US President Donald Trump's former campaign manager is calling for an investigation into a key lawyer on the special counsel team that is currently prosecuting him in two districts.

Attorneys for Paul Manafort filed a motion in Alexandria, Virginia, federal court on Monday evening (May 21) claiming that Mr Andrew Weissmann may have leaked information to the Associated Press in April of 2017, before joining Mr Robert Mueller's investigation into Russian interference in the 2016 election.

At the time, Mr Weissmann led the Department of Justice's criminal fraud division.

Manafort's lobbying on behalf of a pro-Russian political party in Ukraine had been under investigation by the DOJ in Alexandria for years before the special counsel took over the probe and accused him of covering up both the work and the money he made from it.

Manafort's lawyers do not set out details they allege were leaked to the AP.

But the same month that Manafort says Mr Weissmann and other Justice Department officials met with the reporters, the AP reported that Manafort had received at least US$1.2 million (S$1.61 million) in payments listed in a secret ledger detailing spending by former Ukranian president Viktor Yanukovych's Party of Regions.

Manafort helped bring the party to power in 2010.

The so-called "black ledger", found by Ukranian anti-corruption investigators, showed that US$12.7 million had been designated for Manafort between 2007 and 2012 by Mr Yanukovych's party.

Six months after those revelations, the special counsel indicted Manafort, claiming he hid millions of dollars in wire transfers from Ukraine and conducted an illegal lobbying campaign for Mr Yanukovych.

House Intelligence Committee Chairman Devin Nunes, a California Republican, referenced the meeting in a January letter to Deputy Attorney General Rod Rosenstein, saying he understood the Justice Department "is researching records related to the details of an April 2017 meeting between DOJ Attorney Andrew Weissman... and the media".

Spokespeople for the AP and Department of Justice did not immediately return requests for comment. A spokesman for the special counsel declined to comment.

Manafort argues a leak investigation could be limited to "a small number of current and former government officials" who were involved in the Russia investigation at its earliest stage as well as "nine DOJ employees" involved in the Weissmann meeting with reporters.

The filing relies heavily on reporting by Ms Sara Carter, a freelance writer and Fox News contributor sympathetic to the Trump administration.

According to Ms Carter, "the senior DOJ attorney's role in arranging the meeting did not go over well with FBI officials, who issued a complaint to the Justice Department suggesting that the attorney did not follow normal procedures for dealing with journalists".

She also wrote that sources told her Mr Weissmann did not have information about the investigation and had only facilitated the meeting.

A hearing is already scheduled for next month to hear Manafort's motion calling for an investigation into leaks to the media of details about his case.

Mr Mueller's office in court papers has denied the leaks came from the special counsel's office and points to defence attorneys , witnesses and government officials outside the probe as possible sources.

"Manafort's speculative claim of improper conduct falls far short of the showing necessary to warrant a hearing," the prosecutors wrote at the time.

Manafort is arguing that negative press generated by the leaks has poisoned potential jurors for his July 10 trial.

"It seems unlikely that there is a jury questionnaire, instruction or change of venue that could cure the irreparable harm to Mr Manafort's constitutional rights," attorneys Kevin Downing, Thomas Zehnle and Jay Nanavati wrote.

Manafort also faces a Sept 17 trial in DC federal court on related charges.

Meanwhile, both sides are waiting for Judge T.S. Ellis to rule on a motion to dismiss the Virginia case entirely on the grounds that it is outside the scope of the special counsel.