Twitter's new owner Elon Musk appeared to have deleted a tweet posted on Sunday referencing an unfounded theory regarding the attack on the husband of US House Speaker Nancy Pelosi at their San Francisco home.
The since-deleted tweet was in response to one by former Secretary of State Hillary Clinton, who blamed the attack on hateful rhetoric by the Republican Party and linked to an LA Times story about how the suspect promoted far-right conspiracy theories online.
"There is a tiny possibility there might be more to this story than meets the eye," Musk replied to Clinton, linking to a site called the Santa Monica Observer that fact-checkers have described as a purveyor of hoaxes, including that Clinton herself had died and been replaced by a body double.
The Observer did not immediately respond to a request for comment.
Neither Musk nor Twitter immediately responded to a request for comment.
With fears growing of increasing political violence ahead of the Nov 8 midterm elections, Musk's tweet prompted fresh concerns about how he will handle hate speech and misinformation on the social media platform, which the outspoken tech and auto mogul purchased last week for US$44 billion (S$62 billion).
Advertisers will be watching closely. General Motors Co said on Friday, before Musk's now-deleted tweet was posted, it was temporarily halting paid advertising on Twitter after Musk completed his takeover, and that it was engaging with the company "to understand the direction of the platform under their new ownership."
Ad sales accounted for more than 90 per cent of Twitter's revenue in the second quarter.
In a tweet last week, Musk appealed directly to advertisers, saying that under his watch the social network "obviously cannot become a free-for-all hellscape, where anything can be said with no consequences!"
The suspect in the Pelosi attack, David DePape, is due to be charged on Monday with multiple felonies for allegedly clubbing Paul Pelosi over the head with a hammer on Friday after forcing his way into the couple's home shouting "Where is Nancy?"