(Reuters) – U.S. President Donald Trump said in a tweet on Sunday he never asked former FBI director James Comey to stop investigating former national security adviser Michael Flynn.

Flynn is the first member of Trump’s administration to plead guilty to a crime uncovered by special counsel Robert Mueller’s investigation into Russian attempts to influence last year’s U.S. presidential election. Trump fired Comey from his post in May.

“I never asked Comey to stop investigating Flynn. Just more Fake News covering another Comey lie!” Trump tweeted.