Police are aware of one shipment from Christchurch that has made it out of the country and is destined for the UK and Asia, but there may have been more incidents.
Several domains have been shut down by police so far, with the co-operation of overseas domain registering companies, however it appears that the scammers have now registered a domain similar to a New Zealand DHB.
"We are currently aware of three false District Health Board purchase orders that have been sent to separate New Zealand companies requesting goods for delivery to a freight company," said Detective Sergeant Michael Cartwright of the New Zealand police financial crime unit.
"We believe that all District Health Boards could be at risk of being targeted and, due to the large number of suppliers health boards have, we are concerned that this has the possibility to affect a large number of different businesses throughout New Zealand.
"Our advice to businesses is that if you receive an email that seems suspicious in terms of format, numbers, language or delivery addresses, contact the relevant organisation first to verify if it is actually from them before you send anything out."
Poor use of English in the initial email was a common identifying factor for the scam, and the purchase orders often have false phone numbers and email addresses on them, he said.
"We ask that anyone who believes they may have been a victim of this scam, or anyone who has received a suspicious sounding email, please report it to us immediately," said Detective Sergeant Cartwright.
Anyone who believes they may have been a victim of this scam can contact their local police station or report it to Crimestoppers on 0800 555 111.