The central bank injected the funds into Afribank, Finbank, Intercontinental Bank, Oceanic Bank and Union Bank on Aug. 14 and fired their senior management, sending shockwaves through the Nigerian corporate establishment.
"If media reports that you have printed and injected money into the five banks whose management you have sacked is true, this committee will with a sense of responsibility challenge your authority to do so," said Ogbuefi Ozomgbachi, chairman of the House of Representatives banking committee.
The committee asked Sanusi to explain how the central bank could provide the fresh capital without parliament's approval.
The governor defended his actions, saying it was within his powers to impose drastic measures on the five banks, which had built up non-performing loans worth 1.14 trillion naira ($7.6 billion) and risked triggering a systemic banking crisis.
Sanusi has said the funds would be convertible into Tier 2 debt or preference shares and new investors would be found as quickly as possible to recapitalise the five institutions. "The CBN has therefore not contravened any law, including the 1999 Constitution, in the manner it intervened to save the five banks through the injection of fresh capital into their operations," Sanusi said.
Sanusi on Tuesday pledged to resign if he was found to have been fundamentally at fault in his actions.
The regulator last month published a list of firms and individuals, including some of Nigeria's most powerful tycoons, whom it said owed 747 billion naira to the five banks.
The country's anti-corruption police, which has already brought criminal charges against executives from the five banks, has warned some debtors could be prosecuted as conspirators in obtaining loans under false pretences.
Companies and individuals have taken out full-page advertisements in Nigerian newspapers protesting their inclusion on the central bank list and saying the loans they held with the banks were not non-performing.
Jimoh Ibrahim, the business magnate behind Nigeria's Global Fleet Oil and Gas, took out the front 11 pages of The Vanguard daily newspaper on Wednesday denying the central bank's assertion that he owed Oceanic Bank 14.8 billion naira.
"We have instituted a case against the CBN to seek redress over the wrong publication and the incalculable damage the said publication has done to our company integrity," he said.
