The shocking allegations were made by whistleblowers including animal welfare group Kangaroo Island Wildlife Network, which rescues and rehabilitates local wildlife on the South Australian island and was given several of the injured marsupials.
Hundreds of the animals are estimated to have died as a result of their injuries, the group's president Katie Welz said.
"It blows my mind that it's being allowed to happen," she told Seven News on Monday night.
"You can't just kill animals because they're inconvenient."
Harrowing footage broadcast by Seven showed koalas falling from the forest canopy as a result of logging.
The situation on Kangaroo Island has been labelled the "most significant animal welfare scandal in the nation's recent history" and a potential tourism disaster by South Australia's opposition leader.
"It has been a catastrophic thing to see as a former environment minister," David Speirs told reporters on Tuesday.
"To see the mismanagement of our precious wildlife is just heart-wrenching."
The 2019-20 bushfires burnt almost half the island and killed the bulk of its koala population. (David Mariuz/AAP PHOTOS)
Kangaroo Island was named the world's number two must-see region by influential travel guide Lonely Planet in October and is a significant drawcard for South Australia's tourism industry, attracting over 200,000 visitors per year.
Tourism on the island took a massive hit when the 2019-20 bushfires torched almost half the island and killed as much as 80 per cent of its koala population.
The reputational damage from the koala kill risked further hampering the island's recovery, Mr Speirs said.
Independent SA upper house MP Frank Pangallo called on the government to immediately suspend tree felling operations until a satisfactory solution could be found.
"The situation is only going to get worse as those plantations are being cleared and will be returned to agricultural land, so these koalas are going to run out of trees to live in and feed off," he said.
But Mr Pangallo laid the blame squarely at the feet of the previous Liberal government for knocking back an application by the plantation to build a deep-sea port on the island to export its trees, forcing them to return it to agricultural land.
SA Environment Minister Susan Close said inspectors who attended the plantation site in May 2023 found "no evidence of koalas being injured as a result of wilful or negligent actions or breaches of the National Parks and Wildlife Act".
"National Parks and Wildlife Service staff will visit the plantation site again this week to inspect operations," she said in a statement.
Kangaroo Island mayor Michael Pengilly accused whistleblowers of "dramatising things" by overestimating the numbers of animals killed.
"As far as I saw there was only one koala," he told Adelaide radio station 5AA on Tuesday.
"I've been out there. They've got thermal imaging going, they've got spotters with binoculars looking at the trees ahead of where they're cutting them down and I was pretty impressed with what I saw actually."
Mr Pengilly said it was in the interests of the island to remove the blue gums after they acted as an "incendiary device" during the devastating fires.
"We want to see these trees gone, this is a company that's trying to clear them," he said.
Koalas are not native to Kangaroo Island but were introduced during the early 20th century in a bid to safeguard the species' dwindling population on the mainland and have since boomed, with many considering them a pest.
Mr Pengilly said the population had exploded since the fires and were at risk of starvation because they had become overabundant and were exhausting the food base.
8°C