The Guardian confirmed the existence of the bug, which was first reported by 9to5Mac.

The bug turns the phone of the recipient of a FaceTime call into a microphone while the call is still ringing. If the recipient of the call presses the power button on the side of the iPhone – an action that is typically used to silence or ignore an incoming call – their phone will begin broadcasting video to the initial caller.

Apple did not immediately respond to a request for comment from the Guardian. The company told Reuters that it was aware of the problem and would release a software update “later this week”.

The bug comes amid increasing concern over privacy by regulators around the globe.

Apple has attempted to distinguish itself from rival technology companies such as Google and Facebook by boasting about its privacy record. In early January, the company ran a 13-floor billboard in Las Vegas stating, “What happens on your iPhone, stays on your iPhone” during the Consumer Electronics Show.

Until Apple releases its software update, it appears that the best way for iPhone users to protect their privacy is to disable FaceTime in the phone’s settings.

I just tested the FaceTime bug with @juliacarriew. It’s real. You can call someone on FaceTime and listen to their phone’s mic if they don’t pick up. In some cases, you can even observe them through the camera without their knowledge. You can go to settings and turn off FaceTime. pic.twitter.com/WmMWjRwWrt

— Sam Levin (@SamTLevin) January 29, 2019

I just tested the FaceTime bug with @juliacarriew. It’s real. You can call someone on FaceTime and listen to their phone’s mic if they don’t pick up. In some cases, you can even observe them through the camera without their knowledge. You can go to settings and turn off FaceTime. pic.twitter.com/WmMWjRwWrt

— Sam Levin (@SamTLevin) January 29, 2019

 Julia Carrie Wong in San Francisco