Rudy Giuliani said one of Robert Mueller's top prosecutors "tortured" former Trump campaign manager Paul Manafort.

In a conversation about Justice Department and FBI conduct, Giuliani argued there is a double standard in federal law enforcement that protected Hillary Clinton while unfairly punishing people in President Trump's orbit.

Giuliani, himself a former federal prosecutor who became mayor of New York City and later Trump's personal lawyer, told Fox Business's Lou Dobbs on Thursday that former FBI Director James Comey "became a political animal" who was "no longer a prosecutor."

Giuliani criticized Comey for his handling of the case about Hillary Clinton's emails, in which he recommended no charges for the former secretary of state, calling it a "complete fix."

Turning his attention to the FBI's counterintelligence investigation into the Trump campaign's ties to Russia, which Comey oversaw until he was fired in May 2017, Giuliani argued that in this matter, prosecutors put every major witness in jail.

He said prosecutors on Mueller's team "trapped" retired Lt. Gen. Michael Flynn into perjury while Mueller's "pitbull," Andrew Weissmann, "tortured Manafort."

Giuliani also said about Manafort that prosecutors "kept him in solitary confinement for seven months in order to turn him," after noting the immunity deal Clinton's associates got in the case.

"So, you can’t fool me. I know when a prosecutor is corrupt, and it’s a fix," he said.

Manafort pleaded guilty to conspiracy to defraud the United States related to his work in Ukraine and witness tampering, but a judge voided the plea deal for lying in violation of it. Manafort, who spent nine months in what he called "solitary confinement," was sentenced in 2019 to nearly seven years behind bars for violating the Foreign Agents Registration Act and committing conspiracy, tax fraud, bank fraud, and obstruction of justice.

Trump and his allies have criticized the Mueller investigation, which did not find sufficient evidence to establish a criminal conspiracy between the Trump team and the Kremlin, as a "witch hunt."

Weissmann, a former Justice Department official who was known to be the "architect" of the Manafort case, is now an NBC News legal analyst and recently warned that Trump's Justice Department's appointment of an outside prosecutor picked to review the case against Flynn is a ruse to investigate Trump's perceived enemies, including Comey.