Roger Stone on Thursday accused former special counsel Jack Smith of carrying out what he called one of the greatest abuses of power in U.S. history, alleging Smith improperly obtained and reviewed communications involving supporters of President Donald Trump and Republican members of Congress.

Appearing on Newsmax’s “Ed Henry The Big Take,“ Stone said he now views Smith’s investigation as more troubling than the FBI’s investigation into alleged ties between Trump’s 2016 campaign and Russia.

“I used to think the Russian collusion hoax was the greatest single dirty trick in American history,” Stone said.

“But I now believe that Arctic Frost Jack Smith’s investigation could be the greatest single abuse of power in American history.”

Stone alleged the Justice Department used “the full authority of the United States government” to spy on members of Congress.

He claimed Smith had previously said he did not review text messages belonging to dozens of Trump supporters and lawmakers but that it has since emerged he did.

Stone did not provide evidence during the interview to support those claims.

The longtime Republican political consultant also contrasted Smith’s actions with his own criminal case.

Stone was convicted in 2019 on charges that included lying to Congress, obstruction and witness tampering stemming from the investigation into Russian interference in the 2016 election.

His prison sentence was commuted by Trump in 2020, and Trump later granted him a full pardon.

During the interview, Stone argued that none of the inaccurate statements he made to Congress were material because, he said, there was no underlying Russian collusion.

“I was charged with lying to Congress,” Stone said. “Yet no misstatement I made under oath was material.”

Stone said Smith should face prosecution, arguing the investigation raised constitutional concerns over the separation of powers.

“He, as a member of the executive branch at the direction of Merrick Garland, who was denying it, was spying on Republican members of Congress,” Stone said.

Stone further described the alleged conduct as unconstitutional and accused Smith of engaging in what he called “treasonous” behavior.

Smith, who led federal prosecutions related to Trump’s handling of classified documents and efforts to overturn the 2020 presidential election before resigning after Trump’s 2024 election victory, has previously defended his investigations as being conducted in accordance with the law.

Garland also has repeatedly rejected allegations that the Justice Department pursued politically motivated prosecutions.