Apple has banned the release of Google Voice from the iPhone, as well as an app based on the software.
According to the Financial Times, Google confirmed that Voice, as well as another program based on it, had been blocked.
The application, which is available for Blackberry and Google's-own Android operating system, offers users the ability to receive multiple calls at then same time, as well as make cheap international calls.
However, some commentators have questioned Apple's claim that it too closely mimics existing functionality, putting the blame down to Apple's US carrier AT&T.
"I think it's AT&T being concerned about consumers looking to manage their costs," Forrester analyst Charles Golvin told the newspaper. It is not the first time the operator has exerted its influence, with several tethering apps and Skype being blocked or heavily restricted.