The name of the phone, along with two others called the iPhone 8 and iPhone 8 Plus, were reported by two news sites given access to an unreleased version of the iOS operating system.
The information was published ahead of a launch event at Apple’s new headquarters on Tuesday.
The BBC claims to have confirmed an anonymous source was behind the leak to Apple-based publications code9to5Mac and MacRumors.
A reference to iPhone X has fuelled rumours Apple intends to unveil a high-end model alongside more modest updates to its existing handsets.
Other discoveries include images of a new Apple Watch and AirPod headphones, a set-up process for Face ID, and the introduction of Animoji, animated emoji characters.