A beef and sheep farm near Masterton in the Wairarapa has tested positive for the cattle disease Mycoplasma bovis.
The confirmation takes to 36 the total number of infected properties nationwide, said the Ministry for Primary Industries.
The farm was located by tracing animal movements from other M.bovis-affected farms, MPI said in a statement.
All cattle on the property will be killed in agreement with the farmer around timing, MPI said.
The government and farming sectors have agreed that all cattle on infected properties should be culled as part of a drive to eradicate the disease, first diagnosed in the South Island last July.
The disease does not affect humans and milk and meat from affected animals is safe to consume, MPI has said.
The ministry said it expected to find further infected properties as tracing of animal movements continues.
The tally of infected properties has been as high as 38 since MPI tracing began.
The ministry said numbers move around as farms have their infected status revoked following a cattle kill and in the time farmers need to wait until their property is deemed a risk.