The Associated Press has learned that the special counsel running the U.S. investigation into possible ties between President Donald Trump’s campaign and Russia’s government has assumed oversight of an ongoing investigation involving former Trump campaign chairman Paul Manafort.

The investigation by special counsel Robert Mueller may also expand to look into the roles of the attorney general and deputy attorney general in the firing of FBI Director James Comey.

The Justice Department’s criminal investigation into Manafort, who was forced to resign in August amid questions over his past business dealings in Ukraine, predated the election and the counterintelligence probe investigating possible collusion between Moscow and associates of Donald Trump.

The move to consolidate the matters indicates that Mueller is assuming a broad mandate in his new role.