Cape Town - Orcas are killing great white sharks, biologists at Dyer Island Conservation Trust have discovered, after a third great white shark was found washed ashore in the space of six days - this time in Struisbaai, Western Cape.

Alison Towner, biologist at the Dyer Island Conservation Trust, who is currently doing an autopsy on the third shark, confirmed with Traveller24 that Orcas are behind the shark deaths.

SEE: Weekend Wrap: 3 great whites found dead off Cape coast, man billed R20 to pee, more airline offloading drama

Towner says that the third carcass - a 4.2m male white shark – is also missing its entire liver, which is an injury matching the previous two dead specimens.

"We have never seen anything like this. This is a very sad time for us all, nature can be so cruel and the dexterity these enormous animals are capable of is mind blowing - almost surgical precision as they remove the squalene rich liver of the white sharks and dump their carcass," says Towner.

WATCH: Knysna whale shark dies despite rescue efforts

The third deceased white shark washed ashore in Struisbaai on Sunday. (Photo: Marine Dynamics).

Over the past six days, the three great white sharks have been found dead in and around Cape Agulhas between Gansbaai and Struisbaai, according to shark cage diving company Marine Dynamics based in Kleinbaai.

The first shark was found on Wednesday 3 May in Franskraal, then another on Friday 5 May, and the third shark found on Sunday 7 May near Struisbaai.

Another 3.4m male white shark, with big pieces missing out of each flank, that was found on Franskraal beach. (Photo: Marine Dynamics).

SEE: #ShockWildlifeTruths: 3m Great white shark dies as onlookers snap away

Marine Dynamics operates in Kleinbaai, a small harbour town, part of Gansbaai in the Western Cape of South Africa - better known as a hotspot for the Great White Shark and one of the best places in the world to see and dive with these iconic creatures in their natural environment.

"This is a difficult yet fascinating time. Something rarely documented in marine top predator behaviour in South Africa," says Towner. The White Shark Research Group is currently compiling a comprehensive report on the dissection and it will be released as soon as possible.

The fifth white shark carcass and the largest to wash up in Gansbaai since 2012 - a 4.9m female (total length) and estimated weight at 1,110kgs - found on May 3. (Photo: Marine Dynamics).

What to read next on Traveller24:

- Weekend Wrap: 3 great whites found dead off Cape coast, man billed R20 to pee, more airline offloading drama

- WATCH: Explore Antarctica's depths from a whale's eye-view\

- PICS: SA photographer named one of the best Underwater Photographers of 2017