US President Donald Trump has announced the departure of his legal aid Don McGahn Amid growing scrutiny over the outcome of the Russian investigation, Trump’s 17^th aide to leave the White House.

Trump announced on Twitter on Wednesday that White House Counsel McGahn would step down, underscoring the White House’s persistent turmoil.

The announcement comes as many were anticipating the departure. A Trump administration official told The Associated Press that McGahn was unaware of his upcoming dismissal, but had been planning to eventually leave his position.

McGahn had been at odds with Trump over the investigations on alleged Russian interference in the 2016 US presidential election.

Various media outlets had reported that McGahn had threatened to resign last June over tensions with Trump, reporting that Trump had pressed McGahn to fire Robert Mueller from his position of special counsel on the Russian election interference probe.

Recent reports have also surfaced from White House staff that McGahn had cooperated deeply with Mueller’s investigations, giving about 30 hours of testimony in at least three voluntary interviews.

McGahn may have been trying to set the ground for his resignation beforehand by persuading Trump to hire Emmet Flood as head White House lawyer to take his position of White House aide after his resignation, the New York Times has reported from inside White House sources.

Flood had advised former US President Bill Clinton during his impeachment process and many speculate that he may be indeed the lawyer Trump needs who would be more willing to do battle against the Russia investigation team.

White House spokesperson Sarah Sanders ruled out any decision on the replacement. However, she did refer to Flood, explaining that the White House was considering “people like him,” and that Flood is “super well-respected around the building but there’s not a plan locked in place at this point.”

Trumps next choice as his new presidential aide may very well be an important signal of how the White House expects the Mueller investigation to take course.

Mueller’s investigation already has resulted in guilty pleas for several Trump insiders, indictments, cooperation deals and one conviction.

Trump has repeatedly slammed the inquiry as a witch hunt. Russia has also denied meddling in the election.