President Donald Trump’s ally and self-proclaimed “dirty trickster” Roger Stone appeared on the Russian state-funded outlet RT yet again, and pushed Trump’s false claim that former President Barack Obama wiretapped Trump Tower.

In an interview with RT, at least his fifth since 2015, Stone stated that both he and Trump believe that Trump Tower “was under surveillance by the federal government and the intelligence agencies” during the 2016 presidential campaign in “potentially the greatest scandal in American history.” Stone added that if wiretapping did occur, “it is unlikely” it was done “without the permission and knowledge of the President.” He called for a “grand jury” where Obama would be “questioned under oath.” Current and former intelligence officials have said Trump’s charge is false.

During the interview, Stone also disputed the American intelligence community’s consensus that Russia interfered with the 2016 election, claiming, “The mainstream media in this country keeps repeating it ad nauseam despite a stunning lack of evidence,” and bemoaned former national security adviser Michael Flynn’s resignation from his post and Attorney General Jeff Sessions’ recusal from any campaign-related probes. Flynn was ousted after it was made public that he lied to Vice President Mike Pence about discussing sanctions with the Russian ambassador to the U.S. Similarly, Sessions recused himself from investigations of the Russian influence on the election after it was revealed that he also met twice with the Russian ambassador and failed to disclose those meetings when asked under oath during his confirmation hearing.

Stone, a longtime friend, ally, and adviser to Trump, is reportedly under investigation by law enforcement as part of a probe of links between Trump associates and Russian officials during the 2016 campaign. Stone claimed last August that he personally was in communication with WikiLeaks founder Julian Assange. A March 8 report also alleges that he exchanged private Twitter messages with “Guccifer 2.0,” an entity U.S. officials believe was created by Russian officials to publicize emails stolen from the Democratic National Committee (DNC).

This is not Stone’s first interview with RT, a Russian-funded media network that Western countries believe works to “sow doubt about democratic institutions and destabilize the West.” Since June 2015, when Trump launched his presidential campaign, Stone appeared on RT at least four times before this latest interview. He claimed in a 2015 interview that Chelsea Clinton was a “co-conspirator” in the “profiteering” and “bribes” of the Clinton Foundation, and said in a February 2016 RT interview that Jeb Bush “brings out his mother” Barbara Bush “on those rare occasions when she’s sober” and that the Bush family is “like an organized crime family.” In another February 2016 interview, he pushed for the election of Trump and said the U.S needed “to have a leader, to have a president kind of like Comrade Putin.” More recently, he suggested in a January 31 interview that former DNC staffer Seth Rich was murdered over the hacking of the organization’s emails and that the “entire notion that the Russians hacked this election and did so in order to affect the result is a falsehood, is a canard.”

Stone has a decades-long history of employing dirty tricks, was banned from multiple American cable outlets, and regularly spouts violent, racist, and sexist rhetoric, including calling Hillary Clinton a “cunt” and advocating her execution. He has also attacked various media figures, calling them things like “professional negro” and “stupid bitch.” Stone is a discredited researcher and conspiracy theorist who claims that the Clintons and the Bushes secretly murdered dozens and that the collapse of World Trade Center Building 7 was “suspicious.” He believes that President Lyndon Johnson killed President John F. Kennedy, President George H.W. Bush tried to assassinate President Ronald Reagan, and the Clintons killed John F. Kennedy Jr.