The Economic and Financial Crimes Commission (EFCC) was established in 2003, during the administration of former President, Olusegun Obasanjo. It's mandate, as contained in the Economic and Financial Crimes Commission establishment Act of 2004; is to enforce relevant Nigerian laws dealing with the issue of money laundering and other economic crimes. Some of these laws include the Advance fee Fraud and Other Related Offenses Act of 1995; Money Laundering Act of 1995; The Failed Banks (Recovery of Debts) and Financial Malpractices in Banks Act 1994; The Banks and other Financial Institutions Act 1991; and The Money Laundering (Prohibition) act 2004. [http://www.efccnigeria.org/efcc/index.php/about-efcc/the-establishment-act]

On the other hand, The Independent Corrupt Practices And Other Related Offenses Commission (ICPC), was established by the Corrupt Practices And Other Related Offenses Act of 2000. The Commission, which was inaugurated in September 2000, also by former President Olusegun Obasanjo; is charged with:
-Receiving and investigating reports of corrupt offences as created by the Act and in appropriate cases prosecute the offender(s) – Enforcement duties.

-Examining, reviewing and enforcing the correction of corruption-prone systems and procedures of public bodies, with a view to eliminating or minimizing corruption in public life- prevention duties.

-Educating and enlightening the public on and against corruption with a view to enlisting and fostering public support for the fight against it – Education duties. [http://icpc.gov.ng/legislative-background/]

A close examination of both law enforcement agencies shows that it won't be totally out of place to merge the both of them. Financial corruption and 'economic' crimes such as money-laundering don't differ much. Such a merger will further aid the goal of reducing the cost of running the federal government, and minimize unnecessary duplication of functions by these 2 agencies. In addition, I'll suggest that the newly merged super-agency's prosecutorial powers shouldn't be at the behest of the Attorney-General, as the late Yar'Adua wanted. The super-agency should be totally independent in it's prosecutorial functions.

I agree with you. Their functions are related.