Caution: Distressing images

An investigation has been launched after a "koala massacre" was uncovered in Victoria's south-west.

A logging operation at a blue gum plantation near Cape Bridgewater has appeared to have destroyed a local koala habitat.

Conservation group Friends of the Earth has shared images of the incident, which included a number of injured and dead koalas.

Friends of the Earth

"According to our local sources, hundreds of koalas may have been killed or injured during logging activities this week alone," it said in a statement.

"Friends of the Earth is alarmed that such wanton destruction and widespread death and injuries continue to plague the south-west Victorian plantation industry."

A rescue operation, made up of both government workers and volunteers, is now underway to save the remaining koalas.

Friends of the Earth

A spokesperson for Victoria's Department of Environment, Land, Water and Planning (DELWP) confirmed to SBS News the state government is investigating the incident.

"If this is found to be due to deliberate human action, we expect the Conservator Regular to act swiftly against those responsible," she said.

"Wildlife welfare assessment and triage will continue with qualified carers and vets. DELWP will be onsite ensuring resources and expertise is available to continue to care for wildlife injured."

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CEO of the Australian Forest Products Association (AFPA) Ross Hampton confirmed the plantation was being logged last year, but said the land was handed back to a private owner once the koala habitat was found.

"This has nothing to do with forestry ... It's a really terrible thing that's happened. We're appalled," Mr Hampton said.

We're appalled Ross Hampton, Australian Forest Products Association

He said that "very strict protocol" dictated that trees are "not touched if there's a koala present".

"We work incredibly hard through our harvest processes to look after every koala in our blue gum plantations and then to find them hurt and maimed and damaged after we've left the property is really disturbing," he said.

"I can categorically say no one who is an AFPA member was involved in this."

Greens spokesperson for the environment Senator Sarah Hanson-Young said images of the "koala massacre" were "gruesome".

"Australians already heartbroken by the images of burned koalas, will be ashamed and distressed that this is happening," Senator Hanson-Young said.

"We cannot allow anyone to get away with this type of cruelty and harm and it's up to governments to do something to stop it."

Koalas are protected under the Wildlife Act 1975. Killing, harassing or disturbing them can attract a penalty of up to $8,000 and an additional fine of more than $800 per head of wildlife.