Elon Musk suggested on Monday that he could seek a lower price for Twitter Inc, saying that there could be at least four times more fake accounts than what the company has said.

"You can't pay the same price for something that is much worse than they claimed," he said at a conference in Miami.

Musk, who on Friday said his $44 billion deal to buy Twitter was on hold pending information on spam accounts, said that he suspects they make up at least 20% of users - compared to Twitter's official estimates of 5%.

When asked at the conference whether the Twitter deal is viable at a different price, Musk responded, "I mean, it's not out of the question."

"The more questions I ask, the more my concerns grow," he said at the All-In Summit 2022 conference.

"They claim that they've got this complex methodology that only they can understand ... It can't be some deep mystery that is, like, more complex than the human soul or something like that."

Twitter shares extended losses in late afternoon trading following Musk's comments.

The stock dropped more than 8% to close at $37.39, lower than its level the day before Musk revealed his Twitter stake in early April, sowing doubts that the billionaire entrepreneur would proceed with his acquisition of the company at the agreed price.

Twitter Chief Executive Officer Parag Agrawal tweeted earlier on Monday that internal estimates of spam accounts on the social media platform for the last four quarters were "well under 5%," responding to days of criticism by Musk of the company's handling of phony accounts.

Twitter's estimate, which has stayed the same since 2013, could not be reproduced externally given the need to use both public and private information to determine whether an account is spam, he added.

Musk responded to Agrawal's defense of the company's methodology with a poop emoji.

"So how do advertisers know what they're getting for their money? This is fundamental to the financial health of Twitter," Musk wrote.

Musk has pledged changes to Twitter's content moderation practices, railing against decisions like the company's ban of former President Donald Trump as overly aggressive while pledging to crack down on "spam bots" on the platform.

Musk has called for tests of random samples of Twitter users to identify bots. He also said, "there is some chance it might be over 90% of daily active users."

Independent researchers have estimated that anywhere from 9% to 15% of the millions of Twitter profiles are bots.

Twitter does not currently require users to register using their real identities and expressly permits automated, parody and pseudonymous profiles on the service.

It does ban impersonation and spam, and penalizes accounts when the company determines their purpose is to "deceive or manipulate others" by engaging in scams, coordinating abuse campaigns or artificially inflating engagement.

Musk's comments to a private audience could add to concerns about his disclosures of market moving information.

Musk, known for his candid Twitter posts, has a long history of skirmishes with the U.S. Securities and Exchange Commission; recently, a U.S. judge slammed him for trying to escape a settlement with the SEC requiring oversight of his Tesla tweets.

(Reporting by Katie Paul and Hyunjoo Jin in San Francisco and Krystal Hu in New York Editing by Kenneth Li, Leslie Adler, Matthew Lewis and Bernard Orr)