By Aidan Malley

Published: 07:05 PM EST

After an iPhone app developer successfully discovered a workaround for being turned down at the App Store in iTunes, Apple has cracked down and barred an unofficial method as well, potentially raising an anti-competition dispute.

Almerica, the creator of a podcast download and playback tool known as Podcaster, faced a second hurdle in as many weeks when Apple shut down access to creating ad hoc licenses for the utility.

Until this point, the developer had been using the method, originally intended for education and software testing, as an impromptu distribution tactic: new licenses would be created in exchange for a $10 contribution. The approach left out the App Store entirely and consequently left Apple out of its 30 percent revenue from each sale.

While Apple itself didn't attempt to explain its move, the clampdown came after the company rejected Podcaster for reasons still disputed today. The iTunes operator had left Podcaster in limbo for several weeks between July and the end of August, only to turn it down over its alleged duplication of iTunes functionality. Neither the iTunes Wi-Fi Music Store nor the music player in the iPhone and iPod touch firmware offer the ability to download podcasts.

The attempt to shutter Podcaster outside of the App Store has already been labeled a risky precedent by critics, who note that Apple is now attempting to regulate both its official source for its devices' apps but also unofficial routes as well. It echoes similarly controversial moves by Verizon and other carriers who in the past have barred unofficial apps from their phones in an attempt to control all app revenue.

"This puts Apple in a dangerous legal position," says Phone News' Christopher Price. "Before today, Apple had rights to assert that the App Store was only one sales channel, which they had every right to control. Now Apple is asserting rights to control any and all sales channels of software to iPhone and iPod touch owners."

A completely closed development environment such as this is likened to a "walled garden" where the iPhone maker has a virtual monopoly and can shut out viable competitors to its own software.

Apple also shows no plans for a turnaround. Although Almerica has since found that Podcaster's installer still works and that those who already elected to receive the app will obtain a working copy, Cupertino-based Apple has begun attempts to minimize the controversies that trigger such unusual methods in the first place. A recent rejection notice reported at Mac Rumors came with a non-disclosure agreement that prevents discussion of the reasons behind the rejection and so doesn't let this developer or others voice public opposition to their exclusion from the App Store.