Update: The same source has come back with another picture, one that looks slightly more legitimate than the last two.
The new image, sent to Phone Arena, shows the S5 F doing a bit of sunbathing, letting us see that metallic-looking backplate with (at last) some light on it.
However, without any confirmation from Samsung we can't be sure if this is the real deal or not, so garnish with the appropriate amount of salt.
Original story below...
Pictures that allegedly show off a pre-production model have been sent over to Phone Arena showing off a brushed metallic backplate. According to the anonymous tipster, the handset is a tad smaller than the Galaxy S5 with thinner bezels.
He also says the phone packs a Snapdragon 801 inside, but he adds that this will be upgraded to an 805 come launch, aligning with what we've already heard.
Before its reveal there was a lot of talk about the Samsung Galaxy S5 having a QHD, which is why we're willing to believe these Prime rumours have credibility.
Furthermore, we can see a big fat Samsung Galaxy F across the screen in one of the images.
As for the back, Samsung may not actually go full metal but choose to take the LG path with a metallic-aping plastic design instead.
The phone's also rumoured to be rocking out with 3GB of RAM and a 16MP rear camera with OIS
Of course, as ever, don't assume these new pictures are legitimate. But we already have an idea in our heads of what a Prime might look like - and this isn't far off.
- TechRadar's big ol' Samsung Galaxy S5 review