They've spent 30 years and $1 million in legal fees, going all the way to the Supreme Court and beyond.
Brian Walker and Edgar Burns blame their lengthy saga on a lack of compliance with the "discovery" process, a pre-trial procedure in which documents must be provided by one party to the other.
It all started in 1987 when both men owned plant nurseries which were struggling, after a company that sold their trees had its funds seized by its bank - money that Walker and Burns claim was owed to them.
To stay afloat, both men worked the graveyard shift at a Hastings freezing works where they met for the first time.
They soon found they had even more in common than their businesses and an insolvent debtor - a lawyer acting for Mr Walker against the bank that seized his funds, also acted for the bank against Dr Burns.
Walker was largely successful in his case but Burns accepted a less-favourable settlement
"Brian and I compared documents in our parallel cases and found that some key documents in one list were not apparent in the other list and the other way round as well," Burns said.
Burns took his case all the way to the Supreme Court, arguing if he had access to the same documents he would have been more successful.
In 2006 the Supreme Court agreed that the discovery process was incomplete but that the missing documents would have made no difference to his case.
"Somewhat naively we thought, at that moment, the courts themselves or the Law Society would step in and say, 'Right, some untoward stuff has gone on' and they would have done something," Burns said.
"But after some months of waiting nothing happened at all."
So the pair complained to the New Zealand Law Society. Two years later it said it would not launch an investigation.
They then complained to the Ministry of Justice's Complaints Review Officer and, after another lengthy delay, a finding has been issued. But they are gagged from discussing it.
"My primary concern is - the cornerstone of democracy is to have a healthy and just legal system where everyone is treated equally," Walker said.
"If this is what is called equal, then I believe we are in real trouble in this country. I believe that this needs to be investigated and dealt with properly."
The New Zealand Law Society says a lawyer's overriding duty in discovery is to the court, not the client, and documents be provided "as soon as practicable".
"Lawyers must not attempt to obstruct, prevent, pervert or defeat the course of justice," it said.
"A lawyer who acts for a party in proceedings must, to the best of the lawyer's ability, ensure that discovery obligations are fully complied with by the lawyer's client and that the rule of privilege is adhered to.
"A lawyer must not continue to act if, to the lawyer's knowledge, there has been a breach of the obligations by a lawyer's client and the client refuses to remedy the breach."
Walker was still in the plant nursery business but Burns was forced to quit his nursery and became a university lecturer in Australia.