Apple has removed around 5,000 apps from its App Store, including some that it claims feature "overtly sexual" content.
Dozens of developers received a message from Apple stating that the company was refining the guidelines under which the App Store operates, and that content that it had "originally believed to be suitable for distribution" were now no longer deemed appropriate, following "numerous complaints from customers about this type of content".
Jon Atherton, the creator of Wobble iBoobs, said he had received a letter saying his app was being removed from the store.
The letter, from Apple's iPhone App Review team, said that if Atherton made changes to the app so that it complied with the recent changes to Apple's terms and conditions, he could resubmit iBoobs for review.
However, Apple has not confirmed whether it has made specific changes to its App Store rules. Instead, it said it reviews problems on a case-by-case basis.
"Whenever we receive customer complaints about objectionable content we review them," said Apple in a statement.
"If we find these apps contain inappropriate material we remove them and request the developer make any necessary changes in order to be distributed by Apple."
According to AppShopper, which monitors App Store activity, the number of applications being removed each day grew sharply on February 17, with a higher-than-average number of removals taking place over the following days.
Industry insiders believe Apple is cleaning up the App Store ahead of the launch of its iPad tablet, which Apple is hoping to promote as a device for families and schools.
But the move has sparked renewed criticism of Apple's already confusing App Store approval process.
Last year, the company was criticised for banning the Eucalyptus ebook application, because it allowed users to download the Kama Sutra to read on their iPhone.
However, it allowed Baby Shaker, an app in which players violently shook a virtual baby to stop it crying, to go on sale before hastily withdrawing it.
In the latest round of deletions, Daisy Mae's Alien Buffet, a game for the iPhone and iPod touch, has also been removed from the store, allegedly because the cartoon heroine wears a bikini.
Yet the official Playboy app, featuring pictures of scantily clad "playmates", remains on sale, as do dozens of other applications that could be considered to feature "overtly sexual" content.
Telegraph Media Group Limited