Family doctors and the Ministry of Health are criticising a bowel cancer screening test launched on Friday, saying it could worry people unnecessarily.
The test was launched by the Pharmacybrands group, supported by the Beat Bowel Cancer Aotearoa consumer group.
The BowelScreen Aotearoa programme includes a test for traces of blood in faeces.
Pharmacybrands says it is a simple, clinically-proven test costing $60 which offers early screening for bowel cancer. The Beat Bowel Cancer Aotearoa group agrees, saying it may save many lives.
But the Health Ministry says people should see their doctor before having the tests, which could provide false reassurance, or provoke unnecessary anxiety for people.
Its national clinical director for cancer says people need good advice before deciding whether to have tests. John Childs says tests such as the one launched on Friday can give false results, and proper follow-up is essential for those having them.
The Medical Association and the Royal New Zealand College of General Practitioners say they are also worried those tested may not be able to get necessary further investigations, or may face a long wait for them.
Beat Bowel Cancer Aotearoa chairperson Sarah Derrett says its test is needed until there is a full screening programme in place for New Zealanders.
Ms Derrett says the test contains a warning about the possibility of false negatives, and results of the tests will be sent to family doctors.
The Health Ministry says evidence suggests that a properly organised national screening programme could save up to 270 lives a year.
A Government pilot bowel cancer screening programme is to begin in Auckland in October.