Ogbonnaya told an Ikeja Special Offences Court on Tuesday how Emefiele used the bank to move multimillion naira to his wife.
Emefiele is standing trial over abuse of office and alleged $4.5 billion and ₦2.8 billion fraud while in office.
Ogbonnaya, the fifth prosecution witness, was led in evidence by the Economic and Financial Crimes Commission (EFCC) Counsel, Rotimi Oyedepo (SAN).