Gregory Craig.

Gregory Craig has left his role as of counsel in the litigation group at Skadden, Arps, Slate, Meagher & Flom in Washington, D.C., as the firm's ties to Ukraine's former government continue to potentially be of interest to special counsel Robert Mueller III.

Craig, 73, joined Skadden in January 2010 after a year as White House counsel at the beginning of the Obama administration. He was also the lead lawyer behind a controversial report released by the firm in late 2012 about the trial of former Ukrainian Prime Minister Yulia Tymoshenko. Supporters of Tymoshenko, who favored closer ties with the West, claimed her prosecution was politically motivated.

A Skadden employee who answered Craig's phone Tuesday in Washington, D.C., confirmed his retirement from the firm and said she would pass along an interview request. Craig's departure from Skadden—first reported by Above the Law—comes roughly two months after Mueller's team charged former Skadden associate Alex van der Zwaan, the son-in-law of Russian oligarch German Khan, with lying to investigators looking into allegations of Kremlin-backed efforts to influence the 2016 U.S. presidential election.