It's not unusual for images of previously unseen unreleased Games Workshop figures to appear on the internet, and probably the best overall source for these is the Collecting Citadel Miniatures wiki. What is unusual, however, is for new figures to appear in older ranges that might previously have been considered to be completely documented; I recently discovered two figures in Bryan Ansell's collection that fit this criteria.
The figures below are labelled "Arbites" on the front of the tab and "GW 1987" on the rear of the tab. So here I present two unreleased Adeptus Arbites from the Rogue Trader era:
It was only while writing this post that I realised how similar the top figure is to the old Citadel Judge Giant figure, so much so in fact that I think they must share the same base figure (pic on the right taken from the Collecting Citadel Miniatures wiki):
It's not so easy to see in the pic above, but the Arbites still retains an eagle badge on the left breast, but it's not quite the same as the eagle seen on the Judge Giant figure. The crouching figure is reminiscent of some of the Rogue Trader Space Pirates range, but I haven't been able to pin down a donor figure. Oddly, the kneepads of the crouching figure look more like the kind that were found on Citadel fantasy fighters of the era.
I've been looking through the original Rogue Trader rulebook and the Book of the Astronomican and I couldn't find any illustrations of Adeptus Arbites that fit with the above. But what I did find on page 139 of the Rogue Trader rulebook is a description of the Adeptus Arbites which contains the following text:
Their uniforms are basically black leather breeches and jacket, with extra padding at the elbows, knees and shoulders - this helps to emphasise their already considerable bulk. Heavy gloves and boots protect the hands and feet, whilst the head is encased within a simplified and practical version of the helmet worn by the Adeptus Custodes.
And in case you weren't aware, this is what the Adeptus Custodes looked like in the Rogue Trader era (pic taken from the Collecting Citadel Miniatures wiki):
Which fits in nicely with the helmet design of the unreleased Adeptus Arbites. Interestingly, the first Rogue Trader releases also made an appearance in 1987, the same year as indicated on the unreleased figures (scan image courtesy of the Stuff of Legends):
This initial range was minus an Adeptus Arbites figure so it's tempting to think that the unreleased Adeptus Arbites might have originally been destined for this first release, and were either pulled due to a design or casting issue, or were simply overlooked in error or perhaps didn't fit on a mould for some other reason. The Adeptus Ardites that finally made it into design were by Jes Goodwin, and example of which can be seen here:
It seems as if Jes toned down the pointy helmet somewhat...
If anyone can shed a light on these two unreleased figures, or would like to speculate as to their design please feel free to leave a comment.