http://www.nola.com/opinions/index.ssf/2012/05/william_jefferson_once_a_power.html
Update.
The case is most infamous for the $90,000 FBI agents found in the freezer of his Washington D.C. home by FBI agents during a search conducted in August, 2005, several weeks before Hurricane Katrina. The money was most of the $100,000 in cash that a government informant had handed him — as FBI agents videotaped the transfer — money that the agency believed was going to given to then vice president of Nigeria as a bribe. The money never got to the Nigerian VP, and the jury ultimately cleared him on a charge of violating the Foreign Corrupt Practices Act.