A bull shark caught off Swansea at Lake Macquarie has stirred up a social media storm, with a photo of the enormous aquatic predator quickly gaining notoriety.

The image, shared by Offshore Fishing NSW, shows the dead shark hanging after "being gut hooked and a huge fight".

The creature towers over a man pictured beside its carcass, its length more than double his height.

The group reports it was "right off the cleaning tables at Blacksmith".