Power as to matters of evidence (National Assembly)
Section 89(2) · 1999 Constitution (2004 edition)
What Constitution says
(2) A summons or warrant issued under this section may be served or executed by any member of the Nigeria Police Force or by any person authorised in that behalf by the President of the Senate or the Speaker of the House of Representatives, as the case may require.
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 55–56. Original document
Release: draft-c8d50d87fae9. Source scope, review and corrections