The LG Optimus G Pro has been leaked in Japan, revealing that the successor to LG's flagship Optimus G will have a 5-inch HD screen and big battery, Digital Spy reported.

Engadget secured a promotional slide seemingly showing the new phone's design and specifications.

Japan-based Blog of Mobile also separately reported a list of specs for the Optimus G Pro that tallied with Engadget's data.

According to the reports, the Optimus G Pro will run Android 4.1 Jelly Bean, and be powered by a quad-core, 1.7GHz Qualcomm Snapdragon S4 Pro processor, with 2GB of RAM and 32GB of internal storage.

The leaked data indicated that the handset will have a 5-inch, 1920 x 1080 HD screen, a 13-megapixel rear camera and 2.4-megapixel front-facing snapper.

Engadget believes that the Optimus G Pro will weigh in at 160 grams and measure 139mm x 70mm x 10.1mm, and have a 3,000mAh battery to power all that hardware.

The Optimus G Pro could launch in May 2013, and it is expected to debut on Japan's NTT Docomo.