Nigeria's President Bola Ahmed Tinubu has named a US-educated former investment banker as his new central bank chief months after the predecessor was arrested as part of a criminal investigation, the government said on Friday.

Tinubu's appointee, Olayemi Michael Cardoso, is a Harvard graduate and former Citibank director in Nigeria, according to local media reports.

Since the Nigerian leader came to office in May, Tinubu has swiftly implemented reforms to attract more investment to Africa's largest economy as part of his "Renewed Hope" agenda.

"President Bola Tinubu has approved the nomination of Dr. Olayemi Michael Cardoso to serve as the new Governor of the Central Bank of Nigeria (CBN)," the presidency said in a statement.

Lawmakers will have to approve the nomination of Cardoso and a new central bank board.

A major oil producer in Africa and the continent's most populous country, Nigeria is struggling with rising inflation now at 25 percent, high debt and a weakening naira currency.

A former Lagos governor, Tinubu has won praise from investors and foreign governments for his early economic reforms, ending a long-standing subsidy to keep petrol prices low and freeing up the naira.

But the short-term impact has seen fuel prices triple, a sharp depreciation of the naira against the dollar and inflation quicken even as the government asks Nigerians for patience.

Former central bank governor Godwin Emefiele, who critics questioned for his unorthodox policies, was detained by the national security agency in June after Tinubu suspended him. He is still under investigation.