Johannesburg - Three Chinese nationals appeared in the Vosloorus Magistrate court on Monday for possession of perlemoen with an estimated value of R2.1m and operating a fish processing plant without a permit, the NPA said.
The matter was postponed to 2 October for a possible formal bail application, said National Prosecuting Authority Gauteng spokesperson Phindi Louw.
The three have not pleaded.
Louw said neighbours in Van Dyk Park, Boksburg, had complained to the area's community policing forum about a chemical smell from the premises.
On 13 September, Ekurhuleni metro police spokesperson Wilfred Kgasago said the men were arrested at a house in Lemoen Street in the suburb.
Frozen and dried perlemoen were found in the house, which was equipped with large freezers, gas cylinders and various chemicals believed to be used to process the protected marine molluscs.
Kgasago said the men, aged between 20, 23 and 27, had suspect work permits.
They were charged at the Dawn Park police station with possession and dealing in an endangered species, Kgasago said at the time.