Apple has made the group chat function in FaceTime unavailable after users said there was a bug that could allow callers to activate another user’s microphone remotely.

The bug was demonstrated through videos onlineand reported on this week by tech blogs. Apple’s online support page on Tuesday said there was a technical issue with the application and that Group Facetime “is temporarily unavailable.”

Reports said the bug in the video chat app could allow an iPhone user calling another iPhone through Group Facetime to hear the audio from the other handset — even if the receiver did not accept the call.

Apple stated they were working on a fix to the problem.