And now President Muhammadu Buhari's government is saying the new leader has won support from the United States and European governments to find more money spirited away from Nigeria.
Buhari has not been specific about which administrations he plans to probe, but he won office partially on votes of people concerned about corruption under the Jonathan administration.
While Buhari said in his inaugural address that he was not looking to settle scores, analysts say Jonathan's administration will be a likely target for any probe.
"Certainly we hope that he does not go into persecuting people, but certainly some of this corruption is fresh and so deep I do not think that he can avoid it," said Clement Nwankwo, Policy and Legal Advocacy Center executive director.
Corruption has long been cited as one of the reasons why millions of Nigerians remain impoverished, despite the country's production of more oil than anywhere else on the continent.
But even high-profile efforts to win back money, like the recovery of $380 million allegedly stolen by Abacha, announced earlier this year, have not necessarily benefited Nigerians, says Idayat Hassan, executive director of the Center for Democracy and Development.
"The Abacha loot was recovered, lots of loots were recovered, but what in actual fact were those funds used for?" he asked. "That should also be the next step Nigeria will have to focus on."
Buhari recently described the Nigerian treasury as "virtually empty."
This week, the government said it would tap into a special account for excess money made from oil sales to pay down the country's debts
