New Zealand First says it is extraordinary that the Ministry of Health is spending nearly $2 million a year on traditional Maori healing without knowing how many people are being treated or if it is working.
The ministry has contracts with 15 Rongoa Maori agencies, which use traditional healing techniques such as massage and herbal remedies.
In written information to New Zealand First, Associate Health Minister Tariana Turia said their success rate in healing patients is not being monitored or evaluated.
Mrs Turia confirmed that the ministry has spent about $7.6 million funding the services over the past four years.
New Zealand First leader Winston Peters said it is appalling that money is given to services that have no accountability.
A spokesperson for a governance body set up to oversee traditional Maori healing says there are positive results but they are hard to measure.
Percy Tipene, vice-chair of Te Kahui Rongoa Trust, says measuring the benefits is complicated and people need to understand more about the benefits of Rongoa Maori.
Mr Tipene says providers do have a thorough process for judging the results of each individual's healing.