White supremacist and former Ku Klux Klan leader David Duke has been permanently banned from the social media platform Twitter after repeatedly violating its rules against hate speech.

The shutdown of hardcore Nazi sympathizer Duke’s Twitter feed follows a similar ban on his outpourings on YouTube in June. Duke’s final tweet linked to an interview he had conducted with Germar Rudolf, who was convicted of Holocaust denial in Germany.

Other tweets posted by the 70-year-old promised to expose the “systemic racism lie,” as well as the “incitement of violence against white people” by “Jewish-owned media.”

Duke founded the Knights of the Ku Klux Klan organization in 1974 — an openly neo-Nazi outfit that analysts said completed the “Nazification” of the violent white supremacist organization founded a century earlier.

Duke has maintained close contacts with white supremacists and neo-Nazis in Europe throughout his career as a professional racist. In 2006, he traveled to Iran where he addressed a regime-sponsored conference of Holocaust deniers, calling the murder of 6 million Jews by the Nazis “the device used as the pillar of Zionist imperialism, Zionist aggression, Zionist terror and Zionist murder.”

Duke also has a criminal record, having absconded with funds raised for political purposes for his own personal use on more than one occasion. His most recent sentencing was in 2002 when, after spending two years abroad avoiding a feared arrest, Duke agreed to return to the US and pled guilty to felony mail and tax fraud charges. He served 15 months in a federal prison and was fined $10,000.