The move follows on from the launch of the dp2 Quattro earlier this year.
The dp1 Quattro carries a Foveon X3 direct image sensor, designed to deliver an equivalent resolution of 39 million pixels.
The magnesium-bodied camera features a manual focusing ring, built-in raw file processing and a claimed burst rate of seven frames per second.
It is due to arrive in the UK in October, at a price yet to be announced.
Sigma will also use Photokina to showcase some new lenses.
These include a 150-600mm f/5-6.3 DG OS HSM; and a 18-300mm f/3.5-6.3 DC Macro OS HSM.