The fate of a cargo of phosphate headed for New Zealand will be considered at a court hearing in South Africa on Thursday.
The 54,000 tonne shipment was detained earlier this month after complaints it was mined illegally in the Western Sahara, a desert territory controlled by Morocco.
Morocco's right to this land is disputed.
Two independence movements, the Polisario Front and the Saharawi Arab Democratic Republic, have hired lawyers in Port Elizabeth to hear their claim for ownership of the shipment.
The case will be heard before a full bench of three judges before the Eastern Cape division of the High Court of South Africa.
The phosphate was bought by New Zealand fertiliser company Ballance Agri-Nutrients and represents about one eighth of New Zealand's annual needs.