Washington (CNN) In a defiant set of CNN interviews, former Trump campaign aide Sam Nunberg said Monday he refuses to comply with a grand jury subpoena in the Russia investigation.

"Screw that," Nunberg told CNN's Gloria Borger. "Why do I have to go? Why? For what?"

And in a separate interview with CNN's Jake Tapper, Nunberg said he blamed the investigation's existence on President Donald Trump's firing of James Comey as FBI director -- including an interview where Trump said he was thinking about the Russia investigation when he fired Comey and the fact that he held a meeting with top Russian officials in the Oval Office.

"Donald Trump caused this because he's an idiot," Nunberg said.

Seeming to dare the authorities to challenge him on the refusal, Nunberg told Tapper that he would not appear before a grand jury or spend time reviewing his communications in order to comply with the subpoena.

"I'm not cooperating. Arrest me," Nunberg said. "You want to arrest me? Arrest me."

Varied response on Trump

The Trump campaign fired Nunberg in August 2015 after a series of racist Facebook posts came to light, and Nunberg indicated in interviews Monday there was still bad blood between the President and him but that he did not want to spend time cooperating with the investigation and Trump is right to call the probe a "witch hunt."

Nunberg told Borger that he is not refusing to comply in order to protect Trump.

"No I'm not protecting him, but he didn't do anything," Nunberg said. "You know what he did? He won the election."

But Nunberg asserted in the interview shortly afterward with Tapper that he believes special counsel Robert Mueller has "something" on Trump.

"They know something on him," Nunberg said. "... Perhaps I'm wrong, but he did something."

Nunberg added in his interview with Borger that he had already sat down with investigators for close to five and a half hours.

"I'm not going back in," he said.

White House press secretary Sarah Sanders responded to Nunberg's suggestion earlier Monday that Mueller may have something on Trump, saying: "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."

"I definitely think he doesn't know that for sure because he's incorrect," Sanders said regarding Nunberg's claims. "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."

When asked whether he should refuse the subpoena, Sanders said she wouldn't "weigh in" on what anyone outside of the White House should do.

Inside the West Wing, multiple White House officials were watching Nunberg's interviews with rapt attention, and several said they were stunned, calling the interviews "bizarre" and "nuts."

Protecting Stone

Nunberg said he was refusing to cooperate with the subpoena because he believes investigators are trying to get him to impugn controversial Trump ally Roger Stone, who Nunberg called his mentor.

"They want me to testify against Roger," Nunberg said. "They want me to say that Roger was going around telling people he was colluding with Julian Assange."

Stone denied wrongdoing in a statement provided to CNN.

"I was briefly part of the Trump campaign and has [sic] been the President's friend and adviser for decades; and would expect that Mueller's team would at some point ask for any documents or emails sent or written by me. But let me reiterate, I have no knowledge or involvement in Russian Collusion [sic] or any other inappropriate act," Stone's statement read.

The Washington Post said Nunberg provided the paper with an apparent copy of a subpoena seeking documents related to Trump and nine others, and that Nunberg said he was asked to appear before the grand jury in Washington on Friday.

'Not going to get sent to prison'

Nunberg could face steep legal consequences for defying the requests to turn over documents and testify before the grand jury, but he said in an interview Monday evening on CNN's "Erin Burnett OutFront" that he does not expect to face time in prison.

"I'm not going to get sent to prison," Nunberg said.

He called the situation ridiculous and asserted, "Mueller is not going to send me to prison for this."

In the interview, Burnett mentioned speculation about Nunberg's mental state from a Trump ally, who said Nunberg was either drunk or off his medication, and Nunberg dismissed criticism from Trump's orbit.

"I really could care less what the Trump White House has to say about me," Nunberg said.

Nunberg denied having been drinking or being on anything else.

"Besides my meds, antidepressants, is that OK?" Nunberg said.

Nunberg also expressed his irritation at the scope of the document request and said he might offer to share access to his emails.

"Maybe I'll just give them my password, my email password," Nunberg said.

Carter Page

Nunberg expressed annoyance that the subpoena included a request for communications between him and former Trump campaign foreign policy adviser Carter Page, who has become a central figure in stories about the Russia investigation.

Nunberg told Tapper that he thinks Page is a "scumbag," and said he suspects Page of trying to collude with the Russians.

"I believe Carter Page was colluding with the Russians," Nunberg said, adding later, "I think that Carter Page is a weird dude I don't think he should have been involved in that campaign."

Page said in response that he had not watched the interviews, but he called Nunberg's claim that he colluded with the Russians "laughable."

Suspects interest in Moscow pageant

Nunberg said he suspected that investigators would want testimony on the Miss Universe pageant Trump held in Russia in 2013.

"They probably want to know about Miss Universe 2013, if I had to guess," Nunberg said. "There was nothing there, but they want to hear the testimony. They want to hear what other people said, and perhaps other people told them different things than I heard."

Nunberg said Trump's longtime aide Keith Schiller told him that Trump declined an offer from Emin Agalarov to send women to Trump's hotel room at the Moscow event.

"I was told that that idiot Emin had offered to send women up to Trump's room, but Trump didn't want it," Nunberg said. "He doesn't do that. He's too smart for that."

Agalarov is an Azerbaijani-Russian pop star whose father, Aras Agalarov, is a billionaire real estate developer with ties to Russian President Vladimir Putin. Trump partnered with the Agalarovs to hold Miss Universe in Moscow.

CNN previously reported that a representative for the Agalarovs attended a 2016 meeting at Trump Tower that Donald Trump Jr. accepted after being offered potential Russian dirt on Hillary Clinton.

Nunberg, who was no longer working for the campaign at the time of the meeting, said Trump is not telling the truth when he says he had no knowledge of that meeting throughout the campaign.

"I don't know why he went around trying to hide this," Nunberg said. "And he shouldn't have."