San Francisco, California - Conspiracy theories about the assassination attempt on Donald Trump received tens of millions of views on X, researchers said Tuesday, highlighting the potential for extreme falsehoods to go viral on the Elon Musk-owned platform.

The social media site, formerly named Twitter, was flooded with unsubstantiated claims soon after the shooting Saturday at a campaign rally in Butler, Pennsylvania, which left one spectator dead and a bloodied Trump injured in the ear.

Those included unfounded assertions that the assassination attempt had been "staged" or an "inside job," while fingers were pointed at imaginary culprits such as Jews and the Israeli intelligence agency Mossad.

The conspiracy theories were viewed over 215 million times on X, the watchdog Center for Countering Digital Hate (CCDH) said after analyzing a sample of 100 popular posts.

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A majority of the posts did not carry a "Community Note," a crowd-sourced moderation tool that Musk has promoted as the way for users to add context to the tweets, CCDH added.

In the first 24 hours alone, unsubstantiated narratives around the incident amassed more than 100 million views on X, according to the nonprofit research group Institute for Strategic Dialogue.

X did not respond to a request for comment.

Internet hoaxers also falsely identified several people as the shooter – including Italian sports journalist Marco Violi, anti-Trump protester Maxwell Yearick, and comedian Sam Hyde, AFP's fact-checkers reported.

Federal investigators have identified the shooter, who was killed on the scene, as Thomas Matthew Crooks of Pennsylvania.

In the immediate aftermath of the shooting, several social media users voiced confusion as they scrambled to obtain accurate information in what appeared to be a sea of false or misleading posts, which rapidly gained traction.

The trend illustrates the ability of falsehoods to mutate into the viral political discourse on tech platforms, including X, which now offer fewer guardrails as they scale back content moderation.

Researchers say some clout-chasing accounts on the platform have a financial motive to post sensational falsehoods, as X's ad revenue-sharing program incentivizes extreme content designed to boost engagement.

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"In the marketplace of disinformation – which is effectively what a lot of social media platforms have now been reduced to, a marketplace for lies –extreme content is your currency," said Imran Ahmed, chief executive and founder of CCDH.

"The algorithms take the most outlandish content and amplify it exponentially until the entire digital world is flooded with conspiracism, disinformation, and hate."

Researchers have warned about a possible firehose of disinformation in the run-up to the November election, which will take place in a deeply polarized political climate in the US.

"Already, at an early stage in the US electoral cycle, we can see flashing warning signs that social media in the weeks and months ahead will be increasingly chaotic and rife with disinformation," Ahmed said.