The Galaxy S4 Zoom rumours have stepped up a notch following the much-anticipated phone-come-camera being listed by Bluetooth SIG, the special interest group responsible for managing all Bluetooth device classifications worldwide.

It's described as "Samsung mobile phone (SM-C1010)", which fits with previous leaks suggesting that the Samsung Galaxy S4 Zoom had that same model number.

The new Samsung Galaxy S4 Zoom phone will reportedly join a line-up of devices that also includes the Samsung Galaxy S4 Mini and Samsung Galaxy S4 Active, with the latter being the waterproof, more rugged handset revealed by a company executive during the recent Dubai launch of the conventional S4.

SamMobile claimed this week that the Zoom, codenamed SM-C1010, would have a 16-megapixel camera - the recently released S4 has a 13-megapixel sensor. The site added that the sensor on the new camera-centric smartphone would be similar to that in the Samsung Galaxy Camera, released at the tail end of last year.

Unlike the Samsung Galaxy Camera the Zoom will feature a 10x optical zoom, according to Russian site Hi-Tech.Mail.Ru, rather than a 21x optical zoom, in an attempt to save space. 

The Zoom's Bluetooth SIG page doesn't list hardware specifics but does at least show that the phone exists.

Rumours elsewhere on the web suggest the Zoom could be announced at the end of May or the beginning of June.

We will keep you posted.