Under the Ethics in Government Act, departing congressional representatives are required to file a final disclosure form on outside income and gifts within 30 days whether they resign, get voted out or are forced from office. But the Chicago Tribune said it could find no record of Jackson doing so.
Jackson, D-Ill., is scheduled to be sentenced July 1 for using campaign funds to pay personal expenses. He resigned from Congress last November, shortly after being elected to another term.
The Federal Election Commission also has sent Jackson's campaign warning letters about failure to file quarterly reports, the Tribune said.
Martin Bashir resigns from MSNBC over Sarah Palin comments
Toddler uninjured after being knocked over by Obama family dog