A strange moment in the Russia investigation as former Trump campaign aide Sam Nunberg is going back and forth on whether he will testify before a federal grand jury, in a series of interviews.

Nunberg served as a top advisor to President Donald Trump during the early days of his presidential campaign, before being ousted.

He said Monday Special Counsel Robert Mueller had asked for records of his conversations with other key players in the Trump campaign. Mueller is investigating Russian meddling in the 2016 campaign and potential collusion between Russia and Trump campaign officials.

He told sister station Spectrum New York 1 that the subpoena required him to turn over all emails he had with several people like Steve Bannon and Roger Stone and called it "absolutely ridiculous" saying he would not cooperate.

However, he later told the Associated Press that he probably would end up cooperating.

During those interviews, he made some strong suggestions. He told CNN that Trump "may very well have done something during the election with the Russians."

White House Press Secretary Sarah Sanders responded to that.

"I definitely think he doesn't know that for sure because he's incorrect as we've said many times before. There was no collusion with the Trump campaign. Anything further on what his actions are. He hasn't worked at the White House. So I certainly can't speak to him or the lack of knowledge that he clearly has," Sanders aid.

It is not clear what action Mueller will take if Nunberg does not show up before the grand jury.

The Associated Press contributed to this story.