Google’s recent voice search app for iPhone is undoubtedly and amazingly useful, cool and fun, except for that one thing… A company spokesman confirmed on Tuesday for CNET News that the application is actually breaking Apple’s developer terms, which states that undocumented Application Programming Interfaces (APIs) are not to be used when creating an application.

Google may have admitted to using undocumented API, but it denied charges according to which it was linking to private or dynamic frameworks in the Google Mobile application, the same source reports.

We all know how Apple’s changes colors when any of the applications submitted to the App Store breaks the tiniest of rules, so how come Google’s voice search can still be downloaded from the App Store? Apple representatives are the only ones who can answer that, but apparently they are not very talkative at this moment.

Going back to Google, one big question arises: WHY? It is a known fact that creating an application based on undocumented APIs makes it unreliable due to the fact that those APIs are under development and submitted to change, which could cause the application to break.

Despite all that, some developers (including Google) seem to ignore the warning and take that chance. Google did the same, perhaps rushing into getting the app out there. In this particular case, Google’s app uses an API for the iPhone’s proximity server, which is not included in the developer SDK provided by Apple.

How come the app is still on the App Store? At the end of the day, nobody really knows how much time Apple invests in checking the apps provided by developers for the App Store, or how come in Google’s case, it missed to detect that the developer rules have been broken. But we expect to see a reaction from them shortly.