At least 40 animals reportedly died and another 80 are in the care of authorities after timber harvesting on private land at Cape Bridgewater, near Portland in the state's southwest.

But Labor environment spokeswoman Terri Butler said there were no protections for the Victorian koala population because the mammal wasn't listed as a vulnerable species.

Federal protection and biodiversity laws are currently under review, and the deadline for submissions has been extended to April and after the recent devastating bushfires on Austalia's east coast that killed millions of animals.

Ms Butler said existing penalties for animal deaths of this nature were "simply not tough enough".

"National icons like the koala need federal protection, including in instances where their status is not considered to be vulnerable, based on historical data," she said.

"Labor is calling on the federal government to immediately work with the states to implement tougher standards and penalties for instances of this nature, at state and federal level, as a matter of urgency."

In the Victorian case, it's believed vegetation was removed by contractors before the owner undertook further clearing.

Environmental group Friends of the Earth previously claimed there had been reports of hundreds of starving koalas during a logging harvest completed in late December 2019.

The group said this week that people had seen dead koalas being bulldozed into slash piles - mounds of debris.

An investigation is underway by the conservation regulator and environment department and Victorian Premier Daniel Andrews says anyone found to have done the wrong thing will face a "very stern penalty".

Ms Butler said more data was needed to determine threats to Australian species, particularly following the bushfire crisis.

"More than one billion animals have died during the bushfire crisis," she said.

"Labor has called for a comprehensive ecological audit in response."

Australian Associated Press