You may lodge the required HDCA complaint in the timeframe required if you feel an author has breached legal guidelines.Tristan your comments appear to be defamatory and I am surprised the NZ Beekeepers Forum would allow you to keep posting such damaging and inaccurate material, given their stated policies that defamation is unacceptable.
Anyone threatening legal action against an individual is legally required to identify themselves correctly, rather than using a pseudonym and a gmail address used by multiple people. Presumably if you are representing the company concerned, then you should be using both a name and identifying contact details so that we can ensure you are who you are.Continuing this, and a refusal to withdraw your accusations and to apologise may lead to legal action against you.
More information is detailed in the section below