Mr Williams is determined to prove the ongoing existence of the Tasmanian Tiger, and believes the crepuscular marsupials continue to roam around the North-West of Tassie.

Since 2003, Mr Williams has been working on a book about the almost mythical creature, the last confirmed sighting of which was nearly 100 years ago.

"The consensus view is that the animal died out sometime in the 20th century. I don't support the consensus view," Mr Williams said.

He said in researching for his book he has spoken to about 50 witnesses, many of whose accounts he trusts, who claim they have seen the animal alive in the 21st Century.

He has been shown evidence of variable quality which has spurred him to continue the pursuit.

But Mr Williams does not the word of any random punter who saw a large dark shape in the trees - they must be able to describe certain details of the thylacine's iconic appearance.

A self-confessed folklore tragic, Mr Williams 17 years of dedication to the tiger's pursuit is equal parts science and mystery.

If you have seen the Tasmanian tiger, contact Mr Williams on 0416 303 371.