Cesar Flores, 48, was shot three times by a player moments after giving him his marching orders and the killer is still on the loose and the subject of a police hunt
The incident happened in Cordoba, as a player shot the referee just minutes after being dismissed for hitting another player.
Another player, Walter Zarate, was also hit by a bullet and was taken to hospital, though he is not in critical condition.
The referee, Cesar Flores, 48, was killed after being shot three times - once in the head, neck and chest, according to police.
The killer is still on the run and the subject of a police hunt.