Large cat sighting in Western Australia

hi there, recently my friend and I were walking on the bibilmun track in the south west of Western Australia. we were walking on a hill and we same a group of pigs (about 3-5) we didnt take any notice to this because wild pigs are common in this area so we just kept on walking. Then two days later, we were walking into dwellingup, i was in front and i saw a dark cat like animal slowly walk past the track, immediately i thought it was a dog or a pig, but when looking at the way it walked and how long it was i realised it wasn't because it walked more elegantly than a dog would, and it was slower, and with a long tail. this is when i realised i might have seen something different. So about one hour later I heard a noise to my left and looked and saw a black cat (or what looked alot like a black cat) jump of a tree stump and into the surrounding ferns. then i realised that there was a large cat in the area.
I dont think i am alone with these sightings with me hearing of sightings further down on the darling scarp.
I truly belive that there is are large cats in australia, i hope that this can help you in identifying and researching these elusive creatures.thanks