By Oludare Mayowa and Ulf Laessing
LAGOS (Reuters) - Nigeria's central bank (CBN) and law enforcement agencies have launched an investigation into various banking deals after allegations of illegal transactions, it said on Tuesday, and authorities are questioning top executives at several banks.
President Muhammadu Buhari took office a year ago after campaigning on an anti-corruption ticket, and a number of high-profile arrests have been made since then, including several former executives from major state institutions.
"The CBN is also carrying out its own special examinations and investigations to ascertain the veracity of some allegations, as well as the extent and persons that may be involved in such activities," the bank said, giving no details.
"The safety and the soundness of the Nigerian banking industry remains strong," it said.
Last week, the Economic and Financial Crimes Commission (EFCC) said it had obtained a court order to arrest the managing director of Nigeria's Fidelity Bank, Nnamdi Okonkwo, as part of an investigation into transactions in the run-up to the election in which Buhari beat Goodluck Jonathan.
It was not clear whether Okonkwo's arrest was related to Tuesday's statement. Reuters could not immediately contact Okonkwo's legal team.
Fidelity had said last week it had appointed an acting CEO and that it was cooperating in the investigation. The bank declined to comment beyond the statement.
Separately, Sterling Bank, another local lender, said on its website that EFCC agents had questioned its Chief Executive Yemi Adeola and other members of its senior management team.
"It has now become clear that the investigation is related to the banking relationship of a non-bank financial institution that is a client of Sterling Bank Plc," the bank said, noting that it was cooperating with authorities.
Local media also said law enforcement agents had questioned the CEO of Access Bank, Herbert Wigwe, but the bank declined to comment when Reuters called.
An official at the EFCC, asking not to be named, said Fidelity CEO Okonkwo remained in custody and that the agency was still investigating Sterling and Access Bank. He declined to give details, citing the ongoing investigation.