Legislation passed on Thursday has strengthened search and seizure powers in order to crack down on the country's animal tracking system.
The amendment gives the Ministry for Primary Industries (MPI) unprecedented access to farm properties, with more freedom than police, lawyers say.
Agriculture Minister Damien O'Connor told RadioLIVE that the changes are in order to combat non-compliance with the National Animal Identification and Tracing scheme (NAIT), which helps MPI monitor Mycoplasma bovis movement.
"It's to go on and check if they suspect that there's non-compliance. They get a warrant if they know there's non-compliance," he said.
Mr O'Connor says the need for the technical change was discovered recently during M bovis and NAIT investigations.
"There were technical mistakes made in the NAIT Act that meant if officers went onto a property, they weren't able to take property as evidence."
But farmers are concerned that MPI’s new authority is an invasion of privacy. National’s Agriculture spokesman Nathan Guy slammed the rushed legislation, saying it’s not in farmers’ best interests.
Mr O'Connor says there is case law and precedent that means property must be lawfully seized.
"[MPI] can't just take anything. It has to be directly related to the investigation or the issue at hand.
"All we are doing is aligning what happens in the Search and Surveillance Act, with what happens in the NAIT Act,” he said.
Watch the full interview with Damien O'Connor above.