ABUJA, Nigeria — The cash was handed over in large sacks containing $15 million in $100 bills, bags so heavy that the stoop-shouldered civil servant needed help carrying them.
Afolabi Sotunde for The New York Times
James Ibori, the governor of an oil-rich state in southern Nigeria, was so desperate to escape prosecution on corruption charges that he tried to pay off the civil servant, Nuhu Ribadu, Nigeria’s anticorruption commissioner. Mr. Ribadu accepted the money, but it was all a ruse.
A bespectacled former police officer with the no-nonsense style of a G-man, Mr. Ribadu did not keep the money, a remarkable act in a nation where corruption is endemic. Instead he deposited it in a government bank vault, evidence of Mr. Ibori’s many misdeeds, and in 2007 Mr. Ibori was arrested. Ultimately the charges did not stick — the governor was acquitted by a Nigerian court. He was eventually convicted of money laundering and conspiracy to defraud in Britain, where he had stashed a hefty chunk of the hundreds of millions of dollars of oil money he was believed to have embezzled.
The outcome of the case is in many ways an emblem of Mr. Ribadu’s career as a corruption fighter in Nigeria, a country Colin L. Powell once called a nation of “marvelous scammers”: a string of partial victories against a seemingly unbeatable foe.
These days Mr. Ribadu sits at home in a government-issue villa in this prefab 1980s-era capital, ruminating on his next move.
At 53, he has been celebrated inside Nigeria and beyond for his five-year tenure as chief of the anticorruption unit, beginning in 2003.
In that time he built the unit, called the Economic and Financial Crimes Commission, into Nigeria’s largest anticorruption agency, with over 1,200 employees in six offices across Nigeria. He successfully prosecuted in 2005 Tafa Balogun, an inspector general of police who had resigned. Mr. Balogun pleaded guilty to failing to declare his assets. Mr. Ribadu arrested Mr. Ibori, the former governor of Delta State, in December 2007. He prosecuted 10 prominent national public figures, including nine governors.
His reputation gained luster only after he was forced from office in 2008 and into exile after what he said were assassination attempts, after he tried to prosecute corrupt politicians. He was appointed a visiting fellow at the Center for Global Development in Washington and was also a senior fellow at St. Athony’s College, Oxford.
He returned to Nigeria to run for president in 2011, but came nowhere near victory, and since then has struggled to find a place in Nigerian public life. He continues to investigate graft, but with a less prominent platform. His report pointing out large-scale corruption and waste in the country’s oil industry, which was published last year, was ignored by the government that commissioned it.
“One of my very big disappointments,” Mr. Ribadu said intently in an interview here.
Still, he remains a unique figure, prominent in the political opposition and often named as a possible future candidate for office.
“For the generality of the people, he is a dogged anticorruption crusader,” said Femi Falana, a prominent Nigerian human rights lawyer. “For the corrupt elements that constitute the political class, they fear him.”
Since Mr. Ribadu’s abrupt ouster as head of the anticorruption agency, “there is a feeling that the war on corruption is a lost battle,” Mr. Falana said.
The anticorruption fight appears to be on sabbatical in the garden of Mr. Ribadu’s home here.
“Most people you will have encountered will want to ‘settle’ you,” the soft-spoken Mr. Ribadu said in an interview in the garden, using a Nigerian term for a bribe. “Up to my last day at work, people were trying to bribe me. That is the shocking thing.”
Mr. Ribadu began his career as a street police officer in some of Lagos’s rougher neighborhoods, eventually rising to become the chief prosecutor for the Nigerian police. He speaks with a piercing intensity, sometimes clenching a fist to punctuate a point. He grew up deep in Nigeria’s northern hinterland in the town of Yola. It was a devout Muslim household and a “refuge against pain and injustice” that succored persecuted lepers, he wrote in his autobiography.