Apple is facing a lawsuit after a significant bug was discovered in FaceTime which allowed users to eavesdrop on others just by calling their number.

The tech giant disabled the Group FaceTime feature this week as it works to develop a patch to fix the serious privacy breach.

The bug, first revealed by 9to5Mac, allowed an Apple user to call another and listen into their phone’s audio without them actually answering the call. A further issue allowed them to activate the recipient’s front-facing camera if the caller pressed the power or volume buttons.

Initiating the bug was simple and didn’t require any technical expertise. A user just had to initiate a FaceTime call with the victim and before they pick up, start a Group FaceTime call and add themselves to the call. Once they answer and start the conference call, audio from the recipient’s phone could then be heard by the caller, before the recipient had actually accepted the call.

This eavesdropping access would continue until the call was rejected or timed out.

After the bug was widely reported earlier this week, Apple disabled the Group FaceTime feature.

“We’re aware of this issue and we have identified a fix that will be released in a software update later this week,” Apple said in a statement.

The bug was reportedly discovered by an American teenager earlier this month after he tried to organise a Fortnite gaming session with his friend.

His mother said she reported the bug to Apple, meaning the company was likely made aware of the major privacy issue for more than a week before it disabled the feature.

An American lawyer has also filed a lawsuit against Apple for the bug, accusing Apple of negligence, misrepresentation and fraudulent concealment.

Houston-based lawyer Larry Williams II said the flaw caused him professional harm after it allowed for the “recording of a private deposition” with a client.

The lawsuit said this caused him “sustained permanent and continuous injuries, pain and suffering and emotional trauma that will continue into the future” and that he “lost ability to earn a living and will continue to be so in the future”.

The serious privacy breach is extra embarrassing for Apple, which has previously boasted of its privacy practices.

The company even went as far as mocking the privacy standards of its tech rivals at this year’s CES conference, buying a billboard to display the slogan: “What happens on your iPhone stays on your iPhone.”