Authorities are investigating the deaths of more than 100 birds in a Murray River town in the past week.
Wildlife rescuers fear it may be another case of deliberate poisoning.
The deaths of the little corellas, which many people believe to be a pest when they gather in large numbers, occurred in Barmah in NSW, near Echuca.
A second incident involving bird deaths is being investigated at Tocumwal, another river town to the north-east of Barmah.
Some believe the incidents could be linked.
The Victoria government's Conservation Regulator has confirmed the investigation and has asked for public help.
The regulator said it was "working to determine if the deaths were caused by a disease or as a result of human actions".
"Native birds can be attracted to poisoned grain, intended to kill rodents. Killing wildlife by poison is an offence," the authority said.
"Disease, including Psittacine beak and feather disease, has also been a cause of previous native bird deaths in Victoria."
If you have any information about this incident or cases of wildlife crime, please contact Crime Stoppers Victoria on 1800 333 000.
The Conservation Regulator also investigated the killing of up to 100 corellas at another Murray River town in 2020 and found it was likely deliberate.
Investigators all but ruled out the deaths were caused by accident such as spray drift, which had been suggested.
"It is unlikely the cause of death in this instance was from nearby crops being sprayed with insecticide," Victorian government authorities said at the time.
About 100 corellas fell dead from trees at Robinvale, in northern Victoria, on December 1 in 2020.
While corellas have a reputation as a nuisance and destructive to crops and gardens when they gather in large numbers, it is against the law to poison them.
"High concentrations of methomyl - an active ingredient found in various insecticides - was, however, identified in toxicology tests performed on the carcasses."
Methomyl is considered highly important for pest management in some horticulture crops and is widely used against fruit fly.
Killing wildlife by poison is an offence under Victoria's Wildlife Act 1975. A person found guilty can receive penalties of up to $16,522 and/or six months jail.
The government is reviewing those laws with the likelihood more severe penalties will be available in future.