A game-changing lawsuit is being prepared in what may be the most significant development of rugby's concussion battle.
The Herald understands as many as 70 former rugby players could have contributed to the action, including multiple All Blacks, whose lives and livelihoods have been affected by cognitive issues ranging from post-concussion syndrome to suspected chronic traumatic encephalopathy (CTE), a degenerative disease with no cure that can only be diagnosed after death.
Two former All Blacks, Carl Hayman and Geoff Old, told the Herald they have been in contact with British-based lawyers about their post-playing medical conditions.
"From what I understand, it's a pretty ever-growing list of [players]. I think it's going to be something quite substantial that's going to come from it," said Hayman, a 45-test tighthead prop.
Hayman, 41, said he was contacted and offered scans and tests to ascertain the damage he'd suffered over the course of a career where he played in New Zealand, England and France. He declined the offer to undergo testing.
The action is being readied by lawyers in Britain and will likely target several national rugby bodies within that jurisdiction. Sources indicate it will argue that rugby authorities have known about, and subsequently underplayed, the risks associated with repetitive head injuries for decades.
It is not yet known what damages would be sought for those suffering from the after-effects of injuries suffered while playing rugby.
However the legal action will seek to further entrench the need for transparency when dealing with injuries, and for current and future players to be fully educated on the long-term risks of head injuries.
In 2014, America's National Football League (NFL) agreed to a settlement of US$765 million ($1.86 billion) as a result of a class-action lawsuit filed on behalf of 4500 former players. The final agreement allowed for up to US$1b in compensation for retired players with serious medical issues linked to repeated head trauma.
The scale of the rugby action is expected to be much smaller.
One of the New Zealanders in contact with the lawyers filing the suit is former All Black loose forward Geoff Old. He has recently fought a losing battle with the Accident Compensation Corporation (ACC) to have his condition recognised and covered.
"He has no executive function," said his wife, Irene Gottlieb. "On a day-to-day basis he needs assistance to do any administration. He suffers from bone-crushing, all-day headaches and is sensitive to light."
She describes him as a functional adult who needs childlike care.
In October, Old had his claim rejected in an ACC tribunal hearing in front of Judge Chris McGuire due to a lack of contemporaneous evidence. However, the judge added that the decision was "not the end of the matter" and said further assessment may prove a link between post-concussion syndrome and blows to the head.
Old, 64, played mainly in the late 70s and early 80s when injury record-taking was spotty.
"I feel lost," Old said. "All the untreated head knocks and no recovery, that's what's causing my forgetfulness and all-day headaches. It's frustrating and an awful feeling."
Gottlieb said she understood the lawsuit encompassed "about 70 gentlemen, mostly from the UK and I understand there's four or five New Zealanders included in that".
In 2016, a Herald investigation uncovered clusters of former rugby stars who were suffering from dementia. They mostly involved those who had played through the 1960s, when treatment for concussion was at best rudimentary.
The International Rugby Board (as World Rugby was then known) first acknowledged the dangers of head injuries in the mid-70s at a medical conference in Dublin. As a result the three-week stand-down rule was implemented for concussed players.
That blunt instrument for tackling concussion went largely unchallenged until rugby went professional after the 1995 World Cup.
The rivers of money flowing into the game and the associated pressures that brought meant the wants of clubs and coaches were often at odds with the hard-and-fast three-week rule, particularly when it came to star players.
In the early 2000s, the controversial Concussion in Sports Group was established and rugby's administrators chose to follow its recommendations (many other large sporting organisations such as the International Olympic Committee and Fifa adhere to its guidelines).
CISG advocated for a six-day stand down which is the standard time between games for sports that have weekly cycles of matches, including most contact sports.
To put it another way, rugby's compulsory stand down effectively decreased at the same time that science strongly established the dangerous links between head injuries and long-term cognitive difficulties.
Although the signatories of CISG have impressively burnished CVs, recent investigations have uncovered that an extraordinary 32 of 36 expert panellists have paid ties to sports where concussions are a major issue.
Even within that organisation, there has been dissent over the minimisation of the risk of head trauma and its link to CTE.
Dr Bob Cantu, who established the Concussion Legacy Foundation with former wrestler Chris Nowinski and is a signatory to CISG, told the Herald: "I've been very upset with [CISG] statements as regards to CTE and I've let them know that. I disagree with them writing there's no causal link established between repetitive head injury and CTE and leaving it at that … What I lobbied for was that while there is not a direct cause and effect between repetitive head injury and CTE there is an overwhelming causal association or causal link between them.
"That organisation [Concussion in Sport Group] is funded by organisations that have an axe [to] grind so to speak."
- additional reporting, Luke Kirkness