Who administers direct democracy mechanisms at the national level?

Referendum Act, section 3(4)

http://aceproject.org/ero-en/regions/americas/BZ/belize-referendum-act-2012

Section 3 (4) Upon receipt of such Writ, every returning officer to whom the Writ is addressed shall proceed to hold the referendum in accordance with this Act and the directions of the Elections and Boundaries Commission.