A spokesperson for the group of kiwifruit growers looking to sue the Government says they have been subjected to a vicious campaign by Zespri and groups aligned with the marketer.
Zespri says the allegations are nonsense.
A group called The Kiwifruit Claim is looking take court action after a shipment of pollen from China, which biosecurity officers cleared for entry into New Zealand in 2009, was the source of the outbreak.
The vine-killing disease first appeared in an orchard on the outskirts of Te Puke in 2010 and spread over the next two years.
Psa wiped out a gold kiwifruit variety - the industry's most profitable cultivar - and is estimated to have cost the country close to $900 million.
A spokesperson for the group, Matthew Hooton, says Zespri directors and grower body Kiwifruit Growers Incorporated have been trying to intimidate those who want to take part in the class action lawsuit in an attempt to deter them.
"Look, we don't want a tit for tat with Zespri - it's best if some of the appalling behaviour that's been going on is put in the past and growers are given an opportunity to think about this in their own time without intimidation from anyone," he said.
"I've never known such vicious tactics as what has happened over this issue in recent weeks ... people's families have been targeted, people's families have been rung and abused for being part of this. There's a whole lot of completely inaccurate information that's been put out which is just a fantasy."
But a spokesperson for Zespri said Mr Hooton's claims are nonsense. They said Zespri's chairman has raised questions regrading the transparency of The Kiwifruit Claim group, and that is it.