By Katie Marsal

Published: 07:10 PM EST

A professionally-developed alternative to Apple's Safari web browser for iPhone already exists in Opera Software's labs; Apple's guidelines for App Store submissions, however, are allegedly keeping it from seeing the light of day.

Opera chief Jon Stephenson von Tetzchner recently told the New York Times (by way of MacNN) that Opera Mini, one of the company's mobile web browsers for smartphones, has already been ported to the iPhone but can't be released as Apple's rules for the App Store preclude software that replicate the core functionality of the iPhone or iPod touch.

The revelation is an unusual one given Apple's official stance on third-party apps as early as March, when the iPhone Software Developer Kit was first released. The Cupertino, Calif.-based cellphone maker specifically bars third-party interpreters that call on non-Apple frameworks and languages, which by definition would include Opera's web rendering engine. This would have left Opera Software converting software unlikely to be released in the near term.

Still, the news doesn't represent the first instance that Apple has rejected apps that would challenge the usefulness of its own code.

Software developer Almerica last month discovered that a submitted podcast download and playback utility Podcaster was rejected for supposedly replicating iTunes -- even though there was no Apple equivalent on the iPhone at the time. However, a recent leak has suggested that Apple may allow podcast downloads in its upcoming iPhone 2.2 update.