Rel Mekkar was a Cardassian gul in the 24th century.
In 2372, the Detapa Council sent Gul Mekkar to peace talks on Deep Space 9 with the Federation and the Maquis. A case of mistaken identity saw Mekkar be kidnapped and put on trial by the Bajorans, as Vedek Werron thought he was the Butcher of Belmast, a war criminal from the Occupation of Bajor. Julian Bashir was able to prove that Mekkar has been falsely accused, as the real war criminal was a relation of his, Ren Mekkar, and Gul Mekkar was found innocent and released. (DS9 novel: The Heart of the Warrior)