House Oversight Committee chair on Comey's memos: 'I have my subpoena pen ready'

House Oversight Committee Chairman Jason Chaffetz said, "I have my subpoena pen ready," amid reports that fired FBI director James Comey kept memos of conversations with President Donald Trump - one of which suggested Trump asked Comey to drop an investigation into ousted national security adviser Mike Flynn.

"[The House Oversight Committee] is going to get the Comey memo, if it exists. I need to see it sooner rather than later. I have my subpoena pen ready," he wrote in a tweet.

On Tuesday, it was revealed through Comey's memos that Trump had asked Comey to shut down the FBI's investigation into Flynn, who was fired after misleading US officials about his December conversations with a Russian ambassador.

Top congressional officials have suggested Trump's alleged request to Comey could imply that he attempted to influence the Justice Department's and FBI's investigations.

"I hope you can see your way clear to letting this go, to letting Flynn go," Trump said, according to Comey's memo cited in The New York Times. "He is a good guy. I hope you can let this go."

"On the surface that seems like an extraordinary use of influence to try to shutdown an investigation being done by the FBI," said Chaffetz, according to NBC News' Alex Moe.