In a defiant pair 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?"
But Nunberg said that he is not refusing to comply in order to protect President Donald Trump.
"No I'm not protecting him, but he didn't do anything," Nunberg said. "You know what he did? He won the election."
Nunberg asserted in an interview shortly afterward with CNN's Jake 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.
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.
"I'm not cooperating. Arrest me," Nunberg told Tapper. "You want to arrest me? Arrest me."
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.
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."
"They want me to come in to a grand jury for them to insinuate that Roger Stone was colluding with Julian Assange," Nunberg said on MSNBC, referencing Stone, a controversial Trump ally, and Assange, the founder of WikiLeaks.
He continued, "Roger was my mentor. Roger is like family to me. I'm not going to do it."
CNN's Kaitlan Collins and Jeremy Diamond contributed to this report.