Amaka Anajemba, 37, fronted court after pleading guilty to helping defraud a Brazilian bank of A$322 million.
Standing trial with two others, Emmanuel Nwude and Nzeribe Okoli, Anajemba originally pleaded not guilty, but changed her plea in order to receive a shorter sentence.
Anajemba, the widow of the alleged mastermind of the plot, Ikechukwu Anajemba, had her prison term backdated to start in January 2004, when she was first taken into custody.
On top of her jail sentence, Judge Joseph Oyewole ordered Anajemba to forfeit assets worth A$34 million, including properties in Nigeria, the US, Britain and Switzerland.
Anajemba was also ordered pay a sum of A$6.6 million to the government and a fine of A$20,000.
According to court documents, Anajemba helped her husband’s fraud ring trick a leading employee of Banco Noroeste of Sao Paolo siphon off millions of the bank’s funds into overseas accounts.
The duped banker redirected A$322 million over seven years until 2001.
In return, the financier had been promised A$17.8 million in a kickback from a bogus Nigerian airport contract.
The scam is one of several email schemes to originate from Nigeria in recent years, earning the country an unenviable reputation.
Among the best-known frauds were the emails that proposed a share of dead African dictators’ ill-gotten fortunes in exchange for an advance payment to help move the supposed money overseas.
Since 2003, Nigeria’s Economic and Financial Crimes Commission was set up to track down offenders.
Anajemba’s conviction is the first major victory for the commission.
The trial of Anajemba’s codefendants, who have maintained their pleas of innocence, has been postponed until September 13.