Seal of the Inspector General for the United States Department of the Treasury.  The Inspector General serves the entire department with the exception of the IRS, which has its own inspector general.  The design is the same as the Treasury seal with an Inspector General inscription.
Extracted from the PDF version of the OIG's 2002 Annual Plan (direct PDF URL [1]), and colorized according to bitmap in the September 2006 semiannual report (direct PDF URL [2]).
U.S. Government