Update: Nintendo has sent an email to the WSJ denying that it has made any complaint about the app’s similarity to Super Mario Bros.

Apple’n’Apps,  a relatively unknown site without much of a track record, is suggesting that Flappy Bird may have been pulled by Apple after Nintendo complained about copyright infringement regarding the graphics used in the game. Those pipes do look “Super Mario-esque”. The developer Dong Nguyen had claimed he was withdrawing it voluntarily, and that there were no legal issues. But there’s some gray area there we suppose.

A person familiar with the App Store review process tells Apple’N’Apps that Flappy Bird wasn’t removed voluntarily by Mr. Nguyen, as he claims. It turns out that Nintendo got in touch with Apple regarding the art assets in Flappy Bird claiming that they’re in direct violation of their copyrights. Apple contacted Mr. Nguyen regarding the copyright claim, and that’s why we saw the new updated version with graphic changes to the pipes [as well as fewer ads]. Nintendo already decided that they had seen enough, and Apple is the one who pushed Mr. Nguyen to remove Flappy Bird (with 24 hour notice).

We’ve asked Apple for a comment, and will update if we receive a response, though the version arguably makes more sense than a developer voluntarily forsaking around $50,000 a day in revenue due to the attention the game was receiving. Dong Nguyen’s two other games remain on the App Store, currently ranking #4 and #18.

Apple is know to err on the side of caution where copyright complaints are concerned.

The app has also been pulled from Google Play, which tells us nothing either way: if the claim is true then Nintendo would have approached Google also, but equally the developer would have voluntarily removed from both stores.