Between October 1986 and February 1987, the U.S. General Accounting Office reviewed pertinent agency records and interviewed FDA officials regarding policies for conducting criminal investigations and officials' efforts to regulate the counterfeiting and diversion of drugs. This study was occasioned by proposed legislation that would increase the number of activities subject to criminal sanctions under the Federal Food, Drug, and Cosmetic Act. Although the HHS Inspector General has authority to conduct criminal investigations of FDA programs and activities, the investigations relate only to allegations of criminal wrongdoing involving an FDA employee. The HHS Inspector General believes he can take on the added responsibility of more criminal investigations under the proposed legislation without the FDA's having to hire criminal investigators, provide safety officers with criminal investigative training, or relying on other Federal or State agencies. This report recommends that the Secretary of HHS direct the FDA Commissioner and the HHS Inspector General to develop and implement a plan for involving the Inspector General in FDA criminal investigations. Comments from HHS are appended.