The Next Web newswire says that the incident began yesterday morning with an app developer apparently hacking iTunes users accounts and purchasing their own apps using those accounts – thus pushing the apps to the top of the iTunes charts.

"As the story has developed it appears to be far more widespread than just that one particular developer and his apps. We've received a number of reports of accounts being hacked and used to make purchases on iTunes", said the newswire.

Infosecurity understands that the scope of the iTunes problems appears to be limited to the service's US online store.

The Next Web, meanwhile, says that "the rankings in the books category of the US iTunes store features 40 out of 50 apps by the same app developer, Thuat Nguyen."

"What's more concerning is that it seems individuals iTunes accounts have been hacked to make mass purchases of that one developer's apps", said the newswire.

"One look at a screenshot of some twitter search results above or this MacRumors thread should ring alarm bells - there is a problem", the newswire added.

The Yottafire social networking reporting portal, meanwhile, says a Vietnamese hacker – possibly a developer – "somehow got access to the 'books' section of the iTunes app store."

According to a posting by Casey on the portal, the screen shot of the books sections of app store shows some odd names like Conan 1, Conan 2, Conan 7 etc.

Casey went on to say that Apple must now kick out the developer out of the app store and refund the people who have bought the books from the app store today.

Infosecurity notes that overnight reports on the Twitter microblogging service saw users urging other users to change their password on iTunes, as well as removing their card details from the service.