For a report that was written by consultants for a government department, where the department name appears on the title page, include the information about who prepared the report:
DoW (Department of Widgets) (2003). Title of report, report prepared by Smith A & Jones D, DoW, Canberra.
However, if only the name of the consultant appears on the title page, use this name as the author:
Elliston L & Cao L (2004). Managing effort creep in Australian fisheries: an economic perspective, ABARE eReport 04.5, prepared for the Fisheries Resources Research Fund, Canberra.