The management of the Nigeria Police Force has made available a portal where citizens can apply for the character clearance certificate issued by the force.
To apply, interested persons are to follow the procedure outlined below;

PROCESS OF OBTAINING CHARACTER CLEARANCE

1. Visit http://npf.gov.ng/character/
2. Fill the Application form on the right hand side of the portal to obtain an Application ID.
3. Complete the Application Process by Login in with email provided and the Application ID generated.
4. Take the Print-out to the nearest State Police Command Headquarters, and ask of the Forensic Expert for Guidance.
For more information contact: Email: ncis@npf.gov.ng

Source: http://360reporters.com/2016/08/obtain-nigeria-police-character-clearance/