LAGOS, May 10 (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 more top banking executives.
President Muhammadu Buhari took office a year ago, having campaigned 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.
Banking sources say the Economic and Financial Crimes Commission (EFCC) has been investigating several banks for conducting possibly illegal transactions in the run-up to the election in which Buhari beat Goodluck Jonathan.
Corruption spiked under Jonathan but his supporters reject Buhari's claims that his government plundered the treasury.
"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.
Last week, the EFCC said it had obtained a court order to arrest the managing director of Nigeria's Fidelity Bank, Nnamdi Okonkwo. Reuters could not immediately contact Okonkwo's legal team.
Nigerian media outlets, including The Premium Times, citing unnamed sources, said Okonkwo had been arrested on suspicion that he received $115 million from Jonathan's oil minister, Diezani Alison-Madueke. It was not clear if the central bank was referring to these allegations in Tuesday's statement.
Alison-Madueke's lawyer was not immediately available to comment.
She is under investigation over allegations of bribery and money laundering and was questioned by London police in October. Alison-Madueke is still in Britain undergoing cancer treatment, her lawyer has said.
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 that statement.
Separately, Sterling Bank, another domestic 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.
And Access Bank, also a domestic bank, said agents had visited it on Friday to investigate a transaction involving a customer of the bank and questioned its group managing director, Herbert Wigwe.
"He was released without charge on the same day," the bank said in a statement.
An official at the EFCC, asking not to be named, said Fidelity's Okonkwo remained in custody and that the agency was still investigating Sterling and Access Bank. He declined to give details, citing the ongoing investigation. (Additional reporting by Felix Onuah and Camillus Eboh in Abuja; Editing by Louise Ireland)
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