Designers of a health service for sawmill workers exposed to a toxic chemical, have found only a fraction of those believed to be affected.
The chemical penta-chloro-phenol, PCP, was used as an anti-fungal treatment on timber between the 1950s - 1980s.
One study suggested about 10,000 sawmill workers could have been significantly exposed to its toxic effects.
The Ministry of Health has commissioned a consultancy company, Allen & Clarke, to develop a service to treat them.
But a director says only about 200 people have come forward to be registered.
Matthew Allen says the company has to wait for people to identify themselves because the records are so poor.