Federal prosecutors have recently resumed interviewing witnesses in an investigation of two lobbying firms that worked with former Trump campaign chairman Paul Manafort, including one operated by the brother of Clinton campaign chairman John Podesta.

According to The Associated Press, prosecutors in New York have in recent weeks started contacting witnesses and attorneys as part of an investigation into the Podesta Group and Mercury Public Affairs.

The two firms worked with Manafort through 2014 on a consulting project aimed at fluffing the public image of former Ukrainian President Viktor Yanukovych.

Prosecutors have also focused on Greg Craig, the former White House general counsel under then-President Barack Obama and a former partner at the firm Skadden Arps. CNN reported in September that prosecutors were weighing charges against Craig, who has since left his firm. (RELATED: Manafort Indictment Also Implicates Tony Podesta)

Special Counsel Robert Mueller had indicted Manafort on a slew of charges related to his work for a political party close to Yanukovych. Mueller reportedly referred the Podesta and Mercury matters to federal prosecutors in Manhattan.

Neither Tony Podesta, the founder of the Podesta Group, nor Vin Weber, the head of Mercury, have been accused of criminal wrongdoing.

Manafort, 69, was convicted in federal court in Virginia on Aug. 21 on money laundering and tax evasion charges related to his Ukraine profits. He was set to go to trial in Washington, D.C. on charges that he illegal acted as a foreign agent of Ukraine, but the longtime GOP operative entered a plea deal with Mueller’s team on Sept. 14, just before jury selection was set to begin.

Mueller has since moved to nullify that plea agreement, accusing Manafort of lying to prosecutors during meetings after entering the plea deal.

According to court filings submitted in Manafort’s case, the Podesta Group and Mercury Public Affairs failed to register as foreign agents of Ukraine despite knowing that they were working on behalf of Yanukovych.

And at Skadden Arps, Craig helped craft a report aimed at smearing one of Yanukovych’s political rivals.

Follow Chuck on Twitter

Content created by The Daily Caller News Foundation is available without charge to any eligible news publisher that can provide a large audience. For licensing opportunities of our original content, please contact licensing@dailycallernewsfoundation.org.