The chewy sea snail with a distinctive salty taste is popular at feasts and wedding banquets in parts of eastern Asia.

A 53-year-old Chinese national was arrested with two Zimbabweans aged 28 and 31 "in what is believed to be one of the biggest abalone busts in this province in recent years," police in the Western Cape province said.

They confiscated "11,485 wet and 15,200 dry abalone as well as equipment with a total estimated value of 10.3 million rand" (over $550,000), a statement said.

The suspects were arrested on Sunday after police received a tip-off and found a "substantial quantity" of abalone being processed in a large building.

Provincial authorities said they were "pulling the net tighter and tighter to eradicate the illegal distribution and depletion of living marine resources".

In a separate incident, also in the Western Cape, police said they found 2,505 abalones at an abandoned site.

Last month, police arrested a South African man who had plastic bags containing more than 13,000 of the molluscs.

They were worth more than one million rand ($55,000), authorities said.

The volume of illegally caught abalone has almost doubled over the past decade, according to wildlife trade monitoring network TRAFFIC.

Trafficking networks are known to be often run by Chinese criminal syndicates.