22 C.F.R. § 305.8
Section 22 of the Peace Corps Act requires that each Applicant be investigated to ensure that enrollment of the Applicant as a Volunteer is consistent with the national interest. The Peace Corps therefore obtains an appropriate background investigation for all Applicants who are invited to serve in the Peace Corps. Information revealed by the background investigation may be grounds for disqualification from Peace Corps service. Under the Peace Corps Act, if a background investigation regarding an Applicant develops any data reflecting that the Applicant is of questionable loyalty or is a questionable security risk, the Peace Corps must refer the matter to the Federal Bureau of Investigation for a full field investigation. The results of that full field investigation will be furnished to the Peace Corps for information and appropriate action.
22 C.F.R. §305.8