An agricultural chemical used to control mites is believed to have killed hundreds of wedge-tailed eagles in northern Victoria.

Key points: Forensic testing has revealed up to 200 wedge-tailed eagles died from consuming a chemical used to control mites

Forensic testing has revealed up to 200 wedge-tailed eagles died from consuming a chemical used to control mites Several searches of a property near Violet Town have found eagles, other birds, and kangaroo joeys in a freezer and in paddocks

Several searches of a property near Violet Town have found eagles, other birds, and kangaroo joeys in a freezer and in paddocks No charges have been laid, and DELWP cannot say if the poisoning was deliberate

Authorities discovered 120 wedge-tailed eagle carcasses and the remains of other native animals during a raid of a Violet Town property in August.

A further search of the property revealed dozens more eagle carcasses, with the death toll now reaching 200.

Forensic testing by the Department of Environment, Land, Water and Planning (DELWP) revealed the birds died after consuming an insecticide commonly used by farmers.

Community shocked and outraged

The discovery follows multiple reports from the public into bird deaths in the region over the past five years, and is the second mass killing of wedge-tailed eagles in Victoria in two years.

Police and DELWP officers originally discovered the carcasses of wedge-tailed eagles, kites, hawks, falcons, a cockatoo and a kookaburra, as well as a number of kangaroo joeys.

Some of the dead animals were found in a freezer, while the skeletons of hundreds of birds were found in a paddock.

The skeletal remains of a wedge-tailed eagle is one of many found in a paddock near Violet Town. ( Supplied: DELWP )

Samples were taken from the dead birds as well as the carcasses of animals suspected of being used as bait, which also tested positive for the same chemical.

DELWP acting program manager compliance operations Andrew Dean said a further two search warrants were executed at properties in Shepparton East and Goomalibee in late September.

More searches were conducted near Violet Town last week and an additional 47 native birds including 25 wedge-tailed eagles were found, bringing the total number to almost 200.

"While we can't say that any or all of these birds have been deliberately poisoned, given the large number of birds found it's certainly a possibility," Mr Dean said.

"I think it's shocking and the community is outraged."

Deaths point to deliberate act

Wildlife Victoria chief executive Megan Davidson called the event shocking, disturbing and sad.

Authorities would not say why no charges had been laid as yet, but Dr Davidson said the deaths appeared to have been deliberate due to the nature of the circumstances and the number of dead birds found.

"Something on that scale is certainly going to be deliberate. It doesn't sound accidental," she said.

"These are beautiful native animals and they've died in the most horrible way that you can imagine."

Dr Davidson said there was an emerging disrespectful culture in Australia towards native animals and farmers often felt they were competing with the birds for resources, despite the birds being responsible for around 1 per cent of stock deaths.

She said it was difficult to monitor the crime and communities needed to report suspicious activity.

"It's often known in the area or suspected in the area about who is doing this and dobbing in under these circumstances is the right thing to do," Dr Davidson said.

"If you don't report it you might be condemning to death hundreds more animals."

Mass poisonings affecting bird population

Wildlife rescuer Kirsty Ramadan takes care of a dozen eagles at any one time at her wildlife shelter, Bohollow, in northern Victoria.

Many of the eagles are found on the side of roads, on farms, and in paddocks.

Bohollow Wildlife Shelter founder Kirsty Ramadan says eagle poisonings may be impacting upon the population. ( Supplied: Bohollow Wildlife Shelter )

Ms Ramadan said many of the birds' injuries were caused by vehicle and powerline hits, shootings, and poisonings.

While poisonings on a mass scale were rare, she said secondary accidental poisonings of eagles were common across the state.

"Poisoning is horrible to see because the birds present as quite sick, quite unwell, and quite distressed," she said.

"They can have things like internal bleeding, a lack of mobility in their legs and wings — it's very difficult to witness."

Ms Ramadan said she was worried mass poisonings at Violet Town and Gippsland were having a significant impact on the species' population.

"Eagles are lucky to get one chick fledged in a season each year, so it's not as if they're repopulating quickly. To take that many birds out of the population is pretty drastic," she said.

She said poisoned eagles that came through her shelter often did not survive, and her role was to provide palliative care.

"They are beautiful, magnificent birds and they're vital for a functioning healthy eco-system," she said.

"They really have beautiful natures. They're not an aggressive bird while they're in care and most of them settle down pretty quickly. They're very instinct-driven and I always feel very privileged to work with them."