As far as milestones go, this was a bad one for the White House: As we pass the anniversary of the first year of the Trump presidency, special counsel Robert Mueller for the first time interviewed a senior member of the Cabinet–Attorney General Jeff Sessions–in his ongoing investigation into Russian meddling in the 2016 election.

The New York Times reports that Sessions met with Mueller’s team last week for several hours. The interview follows closely on the heels of the special counsel’s decision to subpoena former Trump insider Stephen Bannon.

As both a leader of the president’s transition team and a White House advisor knee-deep in the decision-making process that resulted in former FBI Director James Comey’s ouster, Sessions is likely to be well-informed on the campaign’s alleged contacts with Russia and whether the President took steps, which could rise to the level of obstruction of justice, to undermine the resulting investigation.

Whether Sessions will be forthcoming with investigators, however, is something of an open question. As the Times notes, Sessions recused himself from the Russia investigation last spring (to the president’s great unhappiness) following the revelation that he had not testified accurately about his own contacts with Russian ambassador Sergey Kislyak during Senate confirmation hearings. Last week, Buzzfeed reported that Kislyak’s bank transactions through the Russian Embassy in Washington had drawn the special counsel’s scrutiny, including one large transaction just days after the election, which bank officials flagged as unusual or suspicious activity.

Whether Sessions’ parlay with Mueller turns up new evidence remains to be seen. But it certainly seems to throw doubt on the claims made by Trump’s lawyers that Mueller and his team are close to wrapping up the Russia Probe anytime soon.