WE end this extraordinary financial year with news that the Treasury is in discussions with American International Group about selling the taxpayers’ 80 percent ownership stake in that company. The government recently permitted several banks to break free of its potential oversight by repaying loans made during the rescue. But with respect to A.I.G., the Treasury should not move so fast. There is one job left to do.

A.I.G. was at the center of the web of bad business judgments, opaque financial derivatives, failed economics and questionable political relationships that set off the economic cataclysm of the past two years. When A.I.G.’s financial products division collapsed  ultimately requiring a federal bailout of $180 billion  those who had been prospering from A.I.G.’s schemes scurried for taxpayer cover. Yet, more than a year after the rescue began, crucial questions remain unanswered. Who knew what, and when? Who benefited, and by exactly how much? Would A.I.G.’s counterparties have failed without taxpayer support?

The three of us, as experienced investigators and prosecutors of financial fraud, cannot answer these questions now. But we know where the answers are. They are in the trove of e-mail messages still backed up on A.I.G. servers, as well as in the key internal accounting documents and financial models generated by A.I.G. during the past decade. Before releasing its regulatory clutches, the government should insist that the company immediately make these materials public. By putting the evidence online, the government could establish a new form of “open source” investigation.

Once the documents are available for everyone to inspect, a thousand journalistic flowers can bloom, as reporters, victims and angry citizens have a chance to piece together the story. In past cases of financial fraud  from the complex swaps that Bankers Trust sold to Procter & Gamble in the early 1990s to the I.P.O. kickback schemes of the late 1990s to the fall of Enron  e-mail messages and internal documents became the central exhibits in our collective understanding of what happened, and why.