Fonterra's botulism fiasco has evolved into a finger-pointing exercise.
The research institute which tested Fonterra's whey protein said on Thursday it never told the co-operative its product had bacteria which could cause botulism.
AgResearch has been the subject of criticism since Fonterra told the public the research institute had confirmed a batch of its whey protein was contaminated with clostridium botulinum - forcing it to issue a global recall.
Further testing overseas, found the whey protein didn't have the harmful bacteria - rather a benign cousin.
After not commenting for weeks, AgResearch claimed on Thursday that Fonterra has got it all wrong.
Its communications manager Stephen Doran explained it didn't confirm the presence of clostridium botulinum but it did say that the research had potentially detected clostridium botulinum and so recommended further testing be conducted.
Fonterra is not commenting on the latest revelations.
A spokesperson said the issue will be thoroughly explored in the co-operative's Board-level inquiry and the Government's Ministerial inquiry.
Lincoln University agribusiness professor Keith Woodford said it's highly unsatisfactory that AgResearch and Fonterra are giving completely different accounts of events - and the results AgResearch gave Fonterra need to be made available.
But he said the question still remains did Fonterra act promptly enough when it first realised there was a potential problem with its product ?
"With food safety you must have a recall if there's any chance at all that you have a food safety problem."
He said the reality of this type of testing is there will always be gaps between when you first get the alert and you find out for sure one way or another.