Council contacted the Ministry for Primary Industries (MPI) on the same day but Lynch said they failed to attend.
* Droves of dying koura float down stream * Freshwater stream’s dying crayfish An overseas scientist, made aware by media interest, pointed out to the ministry the deaths could be a result of crayfish plague – a disease not found in New Zealand that would have triggered a quarantine and forced the alert of trade partners, Lynch said.
"There was a tug-of-war over a couple of days between me and MPI because we only had these three koura," Lynch said.
Lynch said although the number of koura collected by regional council staff was small, it satisfied its level of investigation.
MPI investigators had no koura samples to test and were "completely reliant" on council’s work.
But the increased risk of crayfish plague forced council to hand over it’s three samples.
The MPI dissection of tiny animals, at an animal health laboratory in Wellington, found no trace of crayfish plague and left very little else to be tested – less than one gram of koura remained.
The minimum sample for council’s analysis was 20 grams.
Further examination of the stream gave it the all clear.
"We’re surmising that there has been a single strike incident in a tributary upstream and a colony of koura that have been impacted."