Health officials were told five years ago that foreign patients were getting cheap medicines at taxpayers' expense, but it seems they did nothing about it.
Auckland GP Judy Gill says she has a pile of paper showing just how many times she tried to get health officials to do something about the problem.
Gill says GP's computer systems don't allow them to record foreign patients and there is no legal requirement for doctors to record the fact that patients don't qualify for subsidised health care.
The blunder may have been going on for decades and may have seen millions of health dollars wasted before a pharmacist went public to finally get some action.
"Imagine getting ill in the US and going to a drug store and expecting to get subsidised medicine - it just would not happen," Mark Bedford from Dispensary First Pharmacy says.
But in New Zealand foreign visitors have been getting medicines and laboratory tests at bargain basement prices because the computer system used by GPs did not identify them as "not eligible" for subsidies.
Health officials say the problem has only been brought to public attention this month but Dr Gill claims she raised the concerns years ago.
"I get no response no reply so I moved onto the next organisation...last time I made any attempt was in 2004 with HealthPAC," Gill says.
"We're paying tax into a system, we have long waiting lists, have people who can't access herceptin, have a limited health budget. We need to spend it on people who actually need it in our country."
Health Minister David Cunliffe says the general problem with prescription subsidies is long-standing and "probably spans several governments".
And the problem is not just about the computers - one primary practice expert says GPs must take responsibility themselves.
"It's still my responsibility, whether I hand write or computer generate it, to ensure the patient is eligible for the New Zealand subsidies," Professor Murray Tilyard says.
It is unclear exactly just how much money has been wasted but National's health spokesman Tony Ryall believes it's millions of dollars which should have been spent on New Zealanders who have been missing out on medicines.
The ministry's auditors are trying to quantify the problem and see if it is possible to recover the mis-spent money.
"I don't think with all due respect they've got a hope in hell. If I've got back on my cruise ship to the US I don't think I'm going to be worried about sending back a cheque for $30 for diarrhoea pills from 10 years ago," Tilyard says.
