An observant forum poster, warhawke, noticed that “new” STI GP6 pistol bore a striking resemblance to the Slovakian K-100 Grand Power pistol. They are in fact one of the same, although there is no mention of the pistols’ heritage on the STI website (here or here).
I assumed it was a clone by Wikipedia shed some light:
The K100 was designed by Jaroslav Kuracina, a former weapons officer in the Slovak Army. Kuracina sketched drawings of the K100 as early as 1992, but manufacturing activities were highly restricted during the Communist era. Kuracina would be forced to wait until 1996 to continue development of his design. Grand Power has recently announced a deal to produce 100,000 units for the US market.
Now we know where they are sending those pistols! This was further confirmed as I dug around the Grand Power website and found STI listed as the North American dealer.
I certainly do not have a problem with STI rebranding the pistol, but inferring it is a new design and not mentioning its heritage is wrong, in my humble opinion.
UPDATE:
It appears that they did disclose this on a “Skinnergrams” (STI newsletter). Read the comments by S Carruth below.