Three Malawian nationals are being detained by Knysna police after a large quantity of abalone was found in their possession on Sunday.
Spokesperson Sergeant Chris Spies says the suspects were pulled over at a vehicle roadblock outside Sedgefield after 9 pm.
He says a team pulled over a Kia Picanto where officers found 486 units of abalone.
A preliminary investigation indicates that the men aged 28, 34 and 36, were driving from Plettenberg Bay to Cape Town.
All three are expected to appear in the Knysna Magistrates Court on Tuesday.
"Such interventions with the strategic deployment of police and other law enforcement agencies to bring the unlawful harvesting as well as trafficking of the valuable living marine resources along the coast to a halt." said Spies