The Kinjal were a warp-capable species from the Delta Quadrant. One of the technologies they utilized was a polaron modulator, a rare and advanced module not carried on most ships.
A Kinjal frigate was trapped in the the Void up until 2377 when Bosaal murdered the crew, and stole their polaron modulator. (VOY: "The Void")
This species was only mentioned in dialogue.