The UN Board of Auditors (BoA) serves as the external audit body for all UN organizations. The General Assembly appoints three members to the BoA, each of whom must be an Auditor-General (or equivalent) of a Member State.
BoA reports can be found here:
Joint Inspection Unit (JIU): The JIU is an external oversight body mandated to conduct system-wide evaluations, inspections and investigations. The JIU has a unique mandate to look at and identify areas of opportunity in cross-cutting areas. It conducts approximately 10-12 evaluations per year.
JIU reports can be found here: