The Ozenkadnook Tiger Photograph: Rilla Martin's Striped Animal

For generations, people in south-west Victoria and south-east South Australia had talked about a striped animal in the scrub. The sightings went back to the 1880s. The creature took its name from a small locality in the West Wimmera. The Ozenkadnook tiger.

1964. Rilla Martin, from Melbourne, was on holiday in the Goroke district, staying with her cousin. She was driving a dirt track near Ozenkadnook, between Goroke and Apsley. A camera sat on the front seat.

In the woods close to the road, she saw an unusual animal. She compared its size to a Labrador dog. She said it had a pig-like snout. She did not much notice the stripes at the time. She took a single photograph with her box Brownie as it ran from right to left. Then it was gone. Accounts differ on whether she stopped the car first.

The local Wimmera Mail-Times published the picture. The Sydney Morning Herald took it national. Commentators later described a large, quadrupedal predator with a long tail, deep chest, tall shoulders and a rather deep head. Pale stripes crossed the shoulders and the back of the neck.

The original was lent to the newspaper and lost in the 1960s. Only copies survive. Paul Cropper reportedly owns an original print. Another early print later surfaced in the State Library of NSW, catalogued as "Thylacine, Mt. Oliver, n.d.", showing more of the surrounding scrub.

Wildlife experts were quick to denounce it as a fraud. In 1969 a claim surfaced that Martin's cousin had inserted a picture of a "dummy tiger" while developing the film. Darren Naish later suggested that story was an invention. In 1999 her brother, John Martin, denied any hoax: "we country kids hardly knew how to take a photo, let alone fiddle with it."

Naish studied the image in 2010 and 2016. The shoulders looked too high for a thylacine. Leaves overlapped the head. Something beneath the animal might be an artificial support. "Taking photos of running animals from a moving car is maddeningly difficult," he wrote. He suggested a cut-out shape posed in the bush.

24 March 2017. In The Australian, columnist Peter Hoysted, writing as "Jack the Insider", paid tribute to the cartoonist Bill Leak, who had died that month. He wrote that Leak, his father and a friend "fashioned a thylacine shape out of cardboard, painted it up with the stripes roughly in the right places and armed with a box brownie, took a snap of their homemade Tassie Tiger in the scrub." The model was hidden in a shed and later destroyed. The family agreed never to speak of it.

Naish felt the case was edging towards closure. Karl Shuker was not convinced. There was no physical evidence, and nothing explained Rilla Martin's part. Hoysted had only surmised that she agreed to take credit. Shuker called the claim unproven.

The photograph remains a fixture of Australian cryptozoology, reproduced from Living Wonders in 1982 to Naish's Hunting Monsters in 2016. Some saw a surviving thylacine. Others saw Thylacoleo carnifex, the marsupial lion, or a dog striped by light and shadow. One woman. One frame. And a question that has never quite been answered.