The Japanese firm are believed to be following in the footsteps of the likes of Samsung, whose Galaxy Fold smartphone has been pushed back whilst they work on a fault with the screen.
Max J - who is a trusted Samsung analyst - tweeted some of the specifications, which includes a 3220mAh battery and LG Display.
He tweted: "Sony is working on a competitor to the Galaxy Fold and Mate X.
The current prototypes feature:
10x Zoom Camera
The retail models may feature:
Snapdragon 855 Soc
Qualcomm X50 Modem (sic)"
Sony have not commented on the rumour.
Samsung are in the "final stages" of fixing the Galaxy Fold.
The technology giant was originally supposed to launch the new foldable smartphone in April, but following several problems with devices sent to testers for early reviews, the company indefinitely delayed the release of the $2,000 device.
Bloomberg reported that the South Korean hardware firm has now fixed the majority of the issues faced by reviewers, and is now in the "final stages" of the Galaxy Fold's redesign.