A 1921-23 Cyprus half piastre black is expected to dominate the bidding at an upcoming postage stamp auction in London.

The stamp, which was prepared for use but never issued, comes to the July 12 sale with a £55,000 high estimate.

“The most important non-variety stamp of Cyprus”

It is thought to be the last remaining example of the 240 preliminary stamps printed.

The ordinary paper piece, which has been overprinted with "SPECIMEN" in red, features the likeness of George V - Cyprus was under a British administration between 1878 and 1960.

Its only detraction is a short perforation at the foot of the stamp. Its "otherwise fine" condition and unique nature should ensure a strong result. The auctioneer has called it the "most important non-variety stamp of Cyprus."

The finest stamps from the British Commonwealth are among the best collectibles investments around, with the top 30 specimens having shown an 8.5% pa average increase since 1998, according to the Commonwealth Rarities Index.

Paul Fraser Collectibles has recently acquired a fresh range of investment-grade stamps, including arguably the finest Commonwealth stamp in existence. You can see all our stamps for sale here.

The auction will also feature a 1919-21 frame invert from Jamaica. The orange rarity, which still contains the majority of its original gum and features good perforations, has a £30,000 high estimate. The auction house has called it "one of the finest known examples of this popular and striking rarity", with just 10 to 20 thought to exist today from a single sheet printing of 60.

We will bring you full results from the auction later in the week.