The study looked at 485 athletes across contact and non-contact sports
A major study of rugby union players points to a potential link between frequent concussion and brain function, the project's lead researcher said.
The study, funded by World Rugby, was conducted over 29 months and looked at 485 athletes across contact and non-contact sport as well as comparing amateur and professional players with matched control groups.
Despite being "difficult" to draw robust conclusions, the World Rugby organisation said it would require "further research" to confidently link the concussion to brain impairment.
But Professor Patria Hume said it was "irresponsible" to ignore the link.
"If you have a concussion you need to report it and get it medically assessed,” Professor Hume told AFP.
“You also need to consider that potentially there may be some long-term health effects. 94 per cent of elite level rugby players experienced one or more concussions, that’s a lot.”
World Rugby commissioned the study back in 2012 amid growing fears about the potential long-term brain injuries caused by concussion.
The Auckland University of Technology study, which is in the process of being peer reviewed for publication, involved 131 ex-players, 281 retired amateur players and 73 retired non-contact sportspeople.
World Rugby said in a statement: "The study showed that rugby players performed above average in some tests compared to non-contact sports players and less well in others.
"It is therefore difficult to draw robust conclusions about the links between rugby and long-term cognitive health issues and highlights the need for further in-depth research."
But Professor Hume has faith that the study will be validated through a stringent peer review system.
"We've got to go through that scientific process, but what I'm saying is that, as a scientist, it's irresponsible for people to say there are no long-term brain health issues," she said.
"Because all indications so far from the analysis we have done indicates that there possibly are for the rugby players and for people who have been concussed more than four times."
Concussion has come into the spotlight with the occurrences in Irish players like Johnny Sexton and internationally with George North and Richie McCaw.
Even in the United States, US courts have approved a potential billion-dollar settlement in a class action brought by thousands of former American football players against the National Football League.
The players accused it of covering up the dangers of brain injury and is currently under appeal.