The Police Service of Northern Ireland says a 59-year-old man was arrested today on suspicion of the shooting in the village of Kingsmill.
Irish nationalist gunmen stopped a minibus carrying factory workers on January 5, 1976. The men were asked their religion, and the one Catholic in the group was told to run away. The others were shot.
Today's arrest came two months after police announced they had found a potential match to a palm-print found on a getaway vehicle.
