The Confederation of African Football (CAF) said on Friday it would investigate claims that Equatorial Guinea fielded a man in the Africa Women's Championship.
Nigeria lodged a complaint with CAF over 'the gender status' of a player, who was not named.
"The player in question featured for the Equatorial Guinean team at the tournament held from October 31 to November 14 in South Africa," CAF said in a statement on its website.
"The protest has been registered and submitted to the competent committee, CAF Sports Medicine Committee, for inquiries and follow up.
"CAF will provide further information on this case as soon as some other details emerge."
Nigeria defeated Equatorial Guinea in the tournament's final on November 14.
How do you get away with that? Anyways, Nigeria have fielded overage players in youth tournaments before.
