A lawyer with ties to the Obama and Clinton administrations may face federal charges for failing to register as a foreign agent, according to a report.

Greg Craig, 73, a former White House counsel during the Obama presidency, is under investigation regarding whether he improperly worked as a lobbyist for a group associated with Ukraine, without first registering with the Justice Department, CNN reported, citing unnamed sources.

Craig was a partner in the law firm Skadden, Arps, Slate, Meagher & Flom LLP, which may face charges as well, according to the report. Craig left the firm in April, the report said.

An attorney for Craig told CNN his client “was not required to register under the Foreign Agent Registration Act.”

Previously, Craig held several posts in the Clinton administration, including helping to coordinate former President Bill Clinton's impeachment defense, NBC News reported.

The probes of Craig and the Skadden firm are linked to former Trump campaign chairman Paul Manafort, the sources told CNN.

In 2012, Manafort allegedly solicited the Skadden firm in the trial against Yulia Tymoshenko, according to CNN. Tymoshenko was a political rival of former Ukraine President Viktor Yanukovych, who was Manafort’s client at the time.

Craig’s former law firm is also facing criminal charges for its alleged role in Tymoshenko’s prosecution.

CNN said sources claim the Skadden firm was hired to write a report about the Tymoshenko trial. The New York Times reported that Craig was involved in promoting the report to members of Congress and the media -- efforts that would have required Craig to register as a foreign agent, according to the Times.