Elon Musk is claiming that Apple (AAPL) has threatened to remove the Twitter app from its App Store.
In a series of tweets, Musk, who owns Twitter, said that “Apple has threatened to withhold Twitter from its App Store, but won’t tell us why.”
Musk also called Apple’s App Store fees a “secret 30% tax,” and claimed that Apple has pulled most of its advertising from Twitter since he took control of the social media company at the end of October.
The Apple App Store is the only way to distribute software to iPhone devices. If the Twitter app were to be pulled, the social network would lose one of its main distribution platforms.
Apple requires iPhone app makers to pay between 15% and 30% of any digital goods sold through their apps.
Musk has said that he plans for Twitter to raise billions of dollars through subscriptions, such as Twitter Blue, which is offered through the iPhone app. Apple could collect hundreds of millions of dollars in royalty payments from Twitter subscriptions, Musk has said.
Apple has not commented on Musk’s recent tweets or claims about its App Store.
This is not the first time that Musk has publicly criticized Apple. In 2015, Musk said that Apple only hires rejected Tesla employees and that he refers to Apple as the “Tesla Graveyard.”
Apple’s stock is down 21% this year and trading at $144.22 U.S. per share.