Opposition deputies have assured that the birth certificate of Maduro must say that he is the son of a Colombian mother, which would represent the proof that confirms that the president has double nationality and that he cannot hold any office under Article 41 of the constitution. Deputy Dennis Fernández has headed a special commission that investigates the origins of the president and has declared that "Maduro's mother is a Colombian citizen" and that the Venezuelan head of State would also be Colombian. The researcher, historian and former deputy Walter Márquez declared months after the presidential elections that Maduro's mother was born in Colombia and not in Rubio, Táchira. Márquez has also declared that Maduro "was born in Bogotá, according to the verbal testimonies of people who knew him as a child in Colombia and the documentary research we did" and what "there are more than 10 witnesses that corroborate this information, five of them live in Bogotá".