Park rangers came across the damaged theropod footprint at Bunurong Marine Park, a marine park in Victoria, during a school group tour last week.
"It looked like somebody had taken to it with either a hammer or a rock, and had broken off sections of the toes," Victoria parks ranger Brian Martin told the BBC.
According to Martin, it appeared as though the vandals had intentionally targeted the prehistoric three-toed indentation, which is approximately 11 inches wide.
"They would need to know exactly where [the footprint] is to find it. Many people quite easily walk right past it," Martin said.
"For someone to damage it intentionally, you'd have to have a rough idea of where it is because seaweed grows on the rock platform and it looks like a normal rock until you look closely and see the outline of the footprint," Martin also told the Australian Broadcasting Corporation.
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Paleontologists first came across the ancient imprint in 2006 in a tidal rock platform in Flat Rocks, Victoria, an area famous for its thousands of dinosaur fossil bones and teeth.
"The significance of the footprint is that it represents a moment frozen in time when a meat-eating dinosaur stood on that spot and left an impression of its foot," Victoria parks officials said last week, expressing their disappointment at the crime.
Authorities believe they may be able to partially restore the footprint using the broken pieces of rock with a rubber mold taken by paleontologists in 2006 to guide them.