About $1 billion (N157 billion) of the loot by the late Head of State, Sani Abacha, remains out of the reach of Abuja, nearly 13 years after his death, and 12 years after moves to recover the public funds he embezzled and laundered to European countries during his four-year junta.
So far, $1.3 billion is said to have been recovered and lodged with the Central Bank of Nigeria (CBN) with the help of Enrico Monfrini, a lawyer hired by Abuja to help track money that corruptly found its way out of the country during the period.
Part of the outstanding $1 billion has been frozen in Liechtenstein, Luxembourg and The Bahamas.
Part of it is also in France and Jersey in the United Kingdom.
Monfrini disclosed in an interview in the latest edition of FT Weekend Magazine that huge funds laundered systematically are often split into irregular amounts - for instance, an amount such as $7.23 million is first split and routed through other banks across the globe, to make it difficult to trace, before eventually showing up in other destinations.
Monfrini, who is based in Geneva, and who is performing a similar role for Brazil and Haiti, among others, spoke of frustration in the job, having to work day and night for months.
He said: "It is one thing to find and freeze the money, but the next step is to confiscate the funds and repatriate them. This is the hardest part.
"Nobody disputes the cause, but some countries refuse to help, or do not have laws that allow it. To give you a practical example, more than $400 million connected with the Abacha case has been sleeping in the Channel Islands for years, because Jersey is unable - through a lack of laws - to confiscate the money by itself."
Most of the restitution is being monitored by the World Bank as part of efforts to ensure such money finds its way into national coffers, instead of being stolen by equally corrupt state officials.
Monfrini, 66, whose father was a diplomat in Gabon and then Cote d'Ivoire, and has had a close relationship with Africa, first became associated with Nigeria incidentally during the Abacha era, representing several opponents of the despot at the time.
After the death of Abacha, the new government wanted someone trusted that could pursue stolen funds and contracted Monfrini.
"I began with very few details," which only led to empty bank accounts, he recalled, following which he lodged a criminal complaint, which was upheld by the authorities in Geneva.
Accounts traced to Abacha, which had a total $650 million were frozen.
That was the first big break, and since then his work consisted of stripping the accounts, to understand where the money came from and where it went.
Monfrini described himself as a specialist in tracing money embezzled or received through corrupt deals by Heads of State, their entourages, other officials and other public servants.
He said the job is not for the lily-livered, coming with hazards, and with threats from cronies and family members of public officers.
"I might get a phone call, or a visit from a lawyer from Paris or London, who would say: 'Oh, well, you know, Enrico, you should be more careful, because that person didn't at all like what you did to him. He is known to be a rather violent person, with contacts...
"You also need to have a network of friends, which I have built up through the Abacha case. I'm talking of journalists, politicians, policemen, prosecutors, and bankers
"I know lawyers who launder money and they make more than I do. I meet a lot of strange and crooked people, but I also meet a lot of straightforward and important people who want the world to change."
Monfrini believes that in 10 years time such brazen theft of state funds by dictators without regard for the poverty of their people would have stopped.
Nations where stolen funds can still be stashed would soon realise that "it is in their best interest not to give safe haven to corrupt funds."
Closer to home, Economic and Financial Crimes Commission (EFCC) officials are in several states, particularly where Governors have ended their second term or were voted out of office last month.
Many of the Governors are making moves to evade the EFCC ahead of the May 29 handover date.
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