The organization, based in Switzerland, said it is investigating after it emerged Chancel Mbemba Mangulu was registered by his first two Congolese clubs with a 1988 birthday, but had a listed birthday of Nov. 30, 1991, for a Cup of Nations qualifier in June 2011, CNN reported Friday.
His birth date was later recorded by his Belgian club, Anderlecht, as Aug. 8, 1994.
Mangulu has said he believes he was born in 1990.
"We are currently analyzing all the documents at our disposal and investigations against the relevant entities are on-going," FIFA said Thursday in a statement to CNN. "In view of this, we cannot comment any further."