Billionaire Elon Musk said Tuesday that his purchase of Twitter would not go ahead unless he was assured that fewer than five percent of accounts on the platform were fake.
"Yesterday, Twitter's CEO publicly refused to show proof of <5%," tweeted Musk, who has almost 94 million followers on the social network.
"This deal cannot move forward until he does."
The chief of SpaceX as well as Tesla, Musk is currently listed by Forbes as the world's wealthiest person, with a fortune of about $230 billion, much of it in Tesla stock.
Seen by his champions as an iconoclastic genius and by his critics as an erratic megalomaniac, Musk surprised many investors in April with news that he wanted to purchase Twitter.
But his $44 billion buy of Twitter remained "temporarily on hold," pending questions over the social media company's estimates of the number of fake accounts, or "bots."
Twitter chief executive Parag Agrawal said the platform suspends more than a half-million seemingly bogus accounts daily, usually before they are even seen, and locks millions more weekly that fail checks to make sure they are controlled by humans and not by software.