(CNN)President Donald Trump questioned the basis of special counsel Robert Mueller's Russia investigation in a tweet early Saturday morning, alleging that the probe started after former FBI Director James Comey "illegally leaked classified" information.
Trump uses Comey memos to try to discredit Mueller investigation
"James Comey illegally leaked classified documents to the press in order to generate a Special Council? Therefore, the Special Council was established based on an illegal act? Really, does everybody know what that means?" Trump wrote at shortly after midnight.
The President has called the special counsel's probe a "witch hunt" as Mueller investigates whether Trump campaign associates colluded with Russia and any instances of obstruction of justice in the process of the investigation.
After he was fired by Trump, Comey testified before the Senate last year that he provided memos to "a friend" -- Columbia Law School professor Daniel Richman -- to read to the New York Times in hopes it would prompt the appointment of a special counsel to lead the Russia investigation.
The Department of Justice's inspector general is reviewing how Comey handled the memos, including whether any classified information was improperly shared, sources familiar with the matter told CNN.
The inspector general is investigating at least two memos Comey shared with Richman that allegedly contain classified information, The Wall Street Journal reported this week. According to the newspaper, Comey himself redacted portions of one memo before sharing it, and FBI officials later upgraded the classification of the other memo as "confidential," the lowest level of classification.
Comey told CNN's Jake Tapper on Thursday that he could not recall exactly how many of his memos in total were classified.
"I don't know exactly how many there are," Comey told Tapper. "Some may be memos, some may be e-mails. ... And I think some of them -- I know when I created some of them, they were classified, but I don't know how many of that group."