The Justice Department reportedly warned The White House that national security adviser Michael Flynn was communicating with the Russian government and is vulnerable to blackmail, according to the report.

Former acting attorney general Sally Yates informed President Trump’s administration just weeks ago about a possible intelligence breach after Flynn denied that he had discussed sanctions with the Russian ambassador to the US, The Washington Post said.

Flynn, who under intense scrutiny for his alleged ties with Russia, reportedly misled Trump and Vice President Pence about the nature of the phone calls.

Flynn, a former army officer, had numerous communication with Russian Ambassador Sergey Kislyak before Trump took office on Jan. 20.

One call took place on the same day that President Obama levied sanctions against Russia for their alleged interference in the 2016 presidential election.

The Justice Department felt that Flynn had “put himself in a compromising position” by conducting foreign policy as a private citizen, The Washington Post said.

The White House press secretary said Monday night that Trump was “evaluating the situation.”