Environmental authorities have sent DNA samples from thousands of shark fins, confiscated at Cape Town harbour, for testing as part of their investigation.

Marcel Kroese, the head of law enforcement at Marine and Coastal Management, says officials want to establish whether threatened species of fish are involved. Marine officials raided premises on Monday and confiscated more than five tons of dry shark fins.

Sharks have been declining alarmingly across the world as their fins have become prized, particularly in Asia where shark fin soup is a delicacy.