FILE PHOTO: Juan Guaido, President of the Venezuelan National Assembly and lawmaker of the opposition party Popular Will (Voluntad Popular), speaks during a news conference in Caracas, Venezuela January 10, 2019. REUTERS/Carlos Garcia Rawlins/File Photo

CARABALLEDA, Venezuela (Reuters) - Venezuelan intelligence agents have released opposition leader and congress chief Juan Guaido after briefly detaining him on the way to a political rally, a congressional representative said on Sunday.