The Offshore Fishing NSW Facebook group, which originally posted the picture, said the shark was caught with line rated at only 33 pounds and has been submitted as a world record.
The man who caught the shark directed the Newcastle Herald to the Lake Macquarie Game Fishing Club for comment, but official declines to speak to the newspaper.
The comments on the Facebook picture quickly turned into a debate about the morality of not releasing the shark after it was caught.
"Hey guys, been fishing nearly my whole life and catching this huge tiger and killing it is no different than shooting a lion or a bengal tiger. Why not just tag it and let it go," one commenter said.
"What a shame this beauty couldn't sustain his life and become something bigger to be in awe of. Beautiful fish. Sad death," another wrote.
Some commenters were more supportive of the fishermen.
"I often wonder why people who hate fishing and fishermen troll such sites. If it offends you move on or better still embrace diversity, some people believe in different ideals to you. PS top catch well done to all," a Facebook user wrote.
Pending World Record tiger 625.5kg on 15kg... Huge effort off Swansea....Posted by Offshore Fishing NSW on Wednesday, January 27, 2016