New Zealand officials say testing shows they have contained the strain of the highly pathogenic H7N6 avian flu that infected a farm this month.

Mary van Andel, chief veterinary officer at the Ministry of Primary Industries, said in a statement the government had tested farms connected with the first property with the virus and is confident it had been contained to that farm.

"We are on track to stamp out this disease," van Andel said on Tuesday.

The positive test for the virus in December on a chicken farm in Otago, in the South Island was New Zealand's first.

The strain is different from the H5N1 strain, which has spread globally and raised fears of human transmission.

Van Andel said the farm that reported the virus remains under a strict biosecurity lockdown while it undergoes cleaning and decontamination.

New Zealand suspended all poultry exports following the virus's discovery.

Van Andel said the government was in close contact with trade partners and an agreement has been reached with Australia to continue exporting some poultry products.

Slugline