New Zealand fertiliser company Ballance Agri-Nutrients says it is comfortable with the legality and ethics of its phosphate source in the Western Sahara after a $7 million shipment was seized in South Africa.
The NM Cherry Blossom, carrying 50,000 tonnes of phosphate rock, was stopped at Port Elizabeth on Monday amid claims its cargo was illegally taken.
The mineral comes from Laayoune, in the Moroccan-controlled part of Western Sahara which has been under dispute since 1975 when war broke out between Morocco and the Polisario movement fighting for the Sahrawi people.
A lawyer for Polisario in Cape Town, Andre Bowley, says a court hearing over the cargo will be held on May 18.
Ballance chief executive Mark Wynne says it is the first time a shipment had been seized, and it is working with suppliers and lawyers to ensure it gets through.
Ballance had been dealing with Moroccan supplier OCP for nearly 30 years and sourcing phosphate from that area for about 20 of those years, Mr Wynne told NZ Newswire.
The company was comfortable with the ethics and legality of the phosphate source after doing due diligence and consulting with the New Zealand government, he said.
"We take our guidance primarily from the UN Security Council."
He had visited the area last year and Ballance had taken into account the social impact as well as the likes of security of supply.
The NM Cherry Blossom was one of about four annual shipments of phosphate rock which it blends to make fertiliser. It had been due in New Zealand at the end of the month.
Morocco is its main source of phosphate, but also sourced it from China, South Africa and Vietnam.
Contingency plans are underway to ensure farmers will still have fertiliser for spring, Mr Wynne said.
Morocco's government says it does not expect Polisario's legal challenge will succeed.
The hearing should test Polisario's use of a European court ruling last year that said Western Sahara should not be considered part of Morocco in European Union and Moroccan deals, Reuters reports.