Apple disabled the group calling feature in its FaceTime calling service late on Monday evening, as it furiously tries to remedy a bug that allowed eavesdropping.
Apple's status page now shows that Group FaceTime is "temporarily unavailable" as of 3:16 a.m. Tuesday London time (10:16 p.m. Monday ET).
The bug appears to fool a call recipient's phone into thinking a group call, which involves more than two people, has already started. It then switches the recipient's microphone on without them ever having to accept or reject the call.
Despite the temporary removal of the group service, users of FaceTime are still able to continue using the one-to-one FaceTime function.
A spokesperson for Apple told CNBC Monday that a fix is coming this week. "We're aware of this issue and we have identified a fix that will be released in a software update later this week."