Original jurisdiction (Court of Appeal)
Section 239(1) · 1999 Constitution (2004 edition)
What Constitution says
(1) Subject to the provisions of this Constitution, the Court of Appeal shall, to the exclusion of any other court of Law in Nigeria, have original jurisdiction to hear and determine any question as to whether - (a) any person has been validity elected to the office of President or Vice-President under this Constitution; or (b) the term of office of the President or Vice-President has ceased; or (c) the office of President or Vice-President has become vacant.
This is the 1999 Constitution as published in 2004. Later amendments aren't included yet, so a section may have changed since.
Original source
Official Gazette · CFRN 1999 official PDF · printed page 104. Original document
Release: draft-c8d50d87fae9. Source scope, review and corrections