Appointment of Inspector-General and control of Nigeria Police Force
Section 215(3) · 1999 Constitution (2004 edition)
What Constitution says
(3) The President or such other Minister of the Government of the Federation as he may authorise in that behalf may give to the Inspector-General of Police such lawful directions with respect to the maintenance and securing of public safety and public order as he may consider necessary, and the Inspector-General of Police shall comply with those direction or cause them to be compiled with.
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 96. Original document
Release: draft-c8d50d87fae9. Source scope, review and corrections