The data relates, at least in part, to shipments mislabelled as coming from remote Norfolk Island, or Heard Island and McDonald Islands, instead of their correct countries of origin, the Guardian can reveal.

According to an analysis of US import data and shipping records, multiple shipments of goods were classified as having originated from Norfolk Island or Heard and McDonald islands when neither the company address, nor the port of departure for the shipment, nor the destination port were located in those territories.

In some cases involving Norfolk Island, which is 1,600km north-east of Sydney and has a population of 2,188, the confusion appears to have resulted from the fact that the company’s address or port of departure is Norfolk, UK, or the destination is Norfolk, Virginia in the US, or a company’s registered address in New Hampshire (NH) has been listed instead as Norfolk Island (NI).