Cellulose acetate butyrate biocomposites, plasticized with tributyl citrate at volume fraction Vf = 0.1-0.3, were prepared with modified hemp. Inclusion of modified hemp fibres at Vf = 0.4 enhanced the modulus and strength of the flexible plasticized cellulose acetate butyrate. Composites containing pectate lyase enzyme treated fibres showed a modulus greater than untreated or alkali treated fibres, when compared at a similar fibre length of 100 µm. Composites containing the shortest alkali treated fibres of 45 µm gave the greatest property improvement, while 500 µm fibres showed worsened properties. Ball-milled fibres provided reduced values of properties due to cellulose structural disruption, while compression moulding gave better compaction by removing voids.