From Halopedia, the Halo wiki
The Office of Investigations is an organization of the UNSC Naval Command's Logistical Operations Command. Lieutenant Commander Kurt-051 was affiliated with this group as a special attaché, but it is unknown whether this was part of his continued guise as a member of NavLogCom or if it was part of his assignment within the Office of Naval Intelligence.[1]
Unified Earth Government (President of the Unified Earth Government • Secretary of Defense) • Security councils (UEG • UNSC) • Joint Chiefs of Staff