Twitter on Thursday said it had permanently banned Alex Jones, the far-right conspiracy theorist best known for calling the 9/11 attacks an inside job and describing the Sandy Hook school massacre as a hoax.
The social network had been under pressure to remove Jones following similar moves by fellow tech giants Facebook, YouTube, Spotify and Apple last month.
In a series of tweets from its @TwitterSafety account, it said: "Today, we permanently suspended @realalexjones and @infowars from Twitter and Periscope.
"We took this action based on new reports of Tweets and videos posted yesterday that violate our abusive behavior policy, in addition to the accounts' past violations."
Infowars is the website run by Jones. The ban came after Jones traveled to Washington to attend congressional hearings involving Twitter's chief executive officer Jack Dorsey and Facebook's chief operating officer Sheryl Sandberg.
He later posted videos showing himself verbally confronting a CNN reporter as well as Republican Senator Marco Rubio in a hallway.
Reacting to his removal on Infowars, Jones said: "I was taken down not because we lie but because we tell the truth," adding that the incident involving the journalist, Oliver Darcy, may have been the cause of the ban.
Jones harangued Darcy for 10 minutes during the confrontation, calling him a "virus to America" and comparing him to a "possum that climbed out of the rear-end of a dead cow."
Darcy had written an article listing incidents where Jones had violated Twitter's rules.
The ban came a day after President Donald Trump's administration warned of a possible legal crackdown on big technology companies over political bias in a bombshell announcement that came as the Senate hearing concluded.
Trump famously granted Jones an interview during his presidential campaign, telling him: "Your reputation is amazing" and "I will not let you down."
Twitter had previously resisted calls to remove Jones, who had nearly 900,000 followers, though in August it prevented him from posting on his account for a week.