CDHB research nurse Julie Warwick said: "The problem is that this test can be affected by lots of everyday factors and is not always 100 per cent reliable as a predictor of long-term kidney damage."
Prickett said the other test now used measured the creatinine in blood but, while it was a tried-and-true measure, it did not show up until late in the piece.
"What's needed is a reliable test that picks up damage early," he said.
The new test measured the amount of Aminoterminal C-type Natriuretic Peptide in the urine - the amount is higher when the kidneys are injured.
A very small pilot study proved it could be used to accurately to identify diabetic kidney disease in people with serious renal failure but the current trial would determine how early the problem could be detected.
"If it's picked up early enough there's a number of changes which can keep it at bay," Prickett said, citing lifestyle and diet changes as well as useful medication.
The team planned to take urine samples from 200 people in different stages of kidney disease referred through the Christchurch Diabetes Centre.
So far about a third of the samples needed had been collected, he said.
While the trial was for people with diabetic kidney disease, the test should be useful for detecting any type of kidney disease.