A man uses his mobile phone to take pictures of the financial area of Pudong New District (rear) on a smoggy day in Shanghai, China, Nov. 30, 2015. REUTERS/Stringer

Carl Pei, the co-founder of OnePlus, had earlier confirmed that the OnePlus 3 flagship smartphone would arrive by the end of the second quarter of 2016. Speculations indicate that the release date of the smartphone is set in June. Now, leaked photos of the smartphone as well as its retail box have surfaced before its fast-approaching launch date.

A working unit of OnePlus 3 has been spotted on Weibo, the social networking site from China. The rear side of the smartphone sports a sandstone appeal as well as an antenna band on its topside. The front side of the device has a physical "Home" button that probably houses a fingerprint scanner. In an interview to CNET in February, Pei had said the OnePlus 3 will come with a captivating design.

OnePlus 3 is rumored to arrive in two variants. The first model will be a high-end smartphone that will come with specs like Snapdragon 820 SoC, 6 GB of RAM and 64 GB of internal storage. The second model is speculated to be a slightly low-end device with Snapdragon 820 SoC, 4 GB of RAM and 32 GB of native storage.

Both the variants are expected to sport 5.5-inch screens that support full HD resolution of 1,920 x 1,080 pixels. Also, both the smartphones will feature 16-megapixel rear cameras and 8-megapixel front-facing cameras. The Android 6.0.1 Marshmallow OS customized with OyxgenOS is expected to be available preinstalled on OnePlus 3.

Recent rumors have suggested that the base model of OnePlus 3 will be priced at around $310, a cheaper price tag compared to its predecessor. The OnePlus 2 was launched with a starting price of $349.

The OnePlus 3 release date seems imminent as leaked images of retail boxes of the smartphone have surfaced. The images suggest that OnePlus 3 will be made available in different retail boxes for varied markets.