Power to conduct investigations (National Assembly)
Section 88(1)(b) · 1999 Constitution (2004 edition)
What Constitution says
(b) the conduct of affairs of any person, authority, ministry or government department charged, or intended to be charged, with the duty of or responsibility for - (i) executing or administering laws enacted by National Assembly, and (ii) disbursing or administering moneys appropriated or to be appropriated by the National Assembly.
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. Original document
Release: draft-c8d50d87fae9. Source scope, review and corrections