A University of Sydney honorary lecturer and research assistant, Dr Landos was invited on to the inquiry taskforce by Primary Industries and Fisheries Minister Tim Mulherin to “send a clear message we want to get to the bottom of this matter and all possible causes will be considered”.

Dr Landos has now been reported as saying he decided to speak out before the release of the report because he feared the material would be toned down or withheld from the final document.

Fish were found with two heads, no eyes or short tails and Dr Landos was quoted as saying the taskforce evaluated other possible reasons for the mutations, including heat shock and oxygen stress, but they were considered unlikely.

When the fish were protected from spray this season and spawned off-site in uncontaminated water, normal batches were produced, he said.