Despite the existence of the locative/existential copular verbs (see Feature 75 "Predicative locative phrases"), which is the dominant pattern for existentials, o ha(bu), litterally 'it have', or just ha(bu) 'have', is also - marginally - used with existential meaning (see Feature 64 "Expletive subject of existential verb"). This possibly represents Creolese influence.
Source: Kouwenberg 1994: 121
Source: Kouwenberg 1994: 608
Source: Kouwenberg 1994: 377
Source: Kouwenberg 1994: 136