Over the weekend ABC’s Landline broadcast a story about the circumstances leading to the closure of a rural Victorian abattoir, in particular the role of the State authority PrimeSafe and the economic harm caused by the closure to small agribusinesses in the surrounding district. The premise for closing the abattoir was that animals were being treated cruelly. However, cruelty was never proven against the business. I was asked to offer a view about the potential causes of action that the Giles family that owned the abattoir might have against PrimeSafe to recover losses arising from their lost business.
I note (at about 40 minutes) that there are two possible causes of action available to the owners of the abattoir business: negligence and public misfeasance.
Negligence is probably an unlikely cause of action. The High Court, especially following Graham Barclay Oysters Pty Ltd v Ryan  HCA 54, and subsequently the Victorian parliament have directed Australian law away from establishing duties of care being owed by statutory authorities. The difference in this case which might lead a court to deviate from the established trend of the High Court is that the alleged carelessness of the statutory authority was not a failure to act; rather carelessness in exercising its functions (for instance the way it managed and responded to the complaint of animal cruelty against the Giles).
There might be a prospect of success in arguing a case of public misfeasance. This is a rare tort (like the tort of malicious prosecution, with which it shares some features). The tort of public misfeasance is explored in the High Court case of Northern Territory v Mengel  HCA 65. In Mengel, the Northern Territory Department of Primary Industries and Fisheries, through its inspectors, conducted on-farm tests for bovine brucellosis and tuberculosis, leading to financial losses by the Mengels, without the statutory power to do so.
The court held that to establish a public misfeasance it must be proved that the statutory authority or public official acted without statutory power, and did so either with knowledge of the lack of the power or with a malicious intent to cause harm to the plaintiff.
In the case discussed in Landline there may be some doubt whether PrimeSafe had the power under the Meat Industry Act 1993 (Vic) to do as it did in achieving closure of the abattoir. This will require the courts to make a finding of fact about how PrimeSafe procured from the Giles family the abattoir licence. There also appears to be some media commentary that suggests that the authority acted in a manner intending to harm (by shutting down) the abattoir. Whether this was malicious or if PrimeSafe had knowledge about its limited functions would depend on how the courts assess the evidence.