South Africa's high court is selling off a cargo of Western Saharan phosphate on an AM Nomikos bulker at the centre of a long-running legal dispute.

Sealed bids have been invited for the 55,000 tonnes on board the 60,000-dwt NM Cherry Blossom (built 2015), which was arrested last April in a row over the legality of the shipment.

The Polisario Front, the political organisation representing Western Sahara, alleged the phosphate bound for New Zealand was illegally taken from the territory.

The vessel had been chartered by OCP of Morocco, the country which claims sovereignty over the region.

Bidders have 30 days to make an offer.

"An updated laboratory analysis of the samples will be available this week to determine physical and chemical properties of the cargo," Clear Asset Auctioneers' website said.

The starting bid for the cargo was $1m, Reuters reported.

Victory for SADR

Last month, the government of the Saharawi Republic (SADR) in Western Sahara won a court case in South Africa over ownership of the cargo.

The high court ruled that SADR legally owns the whole lot and that Moroccan charterer OCP has never had the legal right to sell it to Ballance Agri-Nutrients, which was also a defendant in the hearing.

The case was the latest development in Polisario's long-running conflict with Morocco over the disputed territory where the two sides fought a war until a 1991 ceasefire and where UN talks have failed to reach an accord.

"We hope there will be significant interest now that the title is clear and is backed by the high court ruling," said Kamal Fadel, an executive member of the Sahrawi Arab Democratic Republic (SADR) Petroleum and Mining Authority.

Proceeds will be used to pursue further legal cases.

"This is just the beginning and we plan to target anyone that deals illegally with our resources," Fadel added.

OCP said last month: "Predictably, the local court in Port Elizabeth, running short of arguments, rendered an unsubstained and unreasoned default summary judgement in the Cherry Blossom case."

It added it did not recognise the competence of the South African court to rule on the matter.

"This pirated cargo rightfully belongs to [subsidiary] Phosboucraa. The group will proudly continue to contribute to the socio-economic development of Morocco, from north to south."