“After the game someone ran onto the pitch and I made an error in judgement and played a part in stopping him,” Cane wrote. “I acknowledge this was not my role and it is out of character of me to act in such a way.
“I am really sorry and am disappointed in myself. I am trying my best to contact the individual to apologise and make things right.”
Later in the day, Cane added in an update on Instagram that he had succeeded in reaching the fan.
“Through the help of many good people, I managed to track down Roman,” he wrote. “Had a good catch up with him and his friends and I’m glad that we could leave things in a good place.”
New Zealand Rugby has been approached for comment about the incident, which marred an excellent performance from the All Blacks as they thrashed Argentina 41-12 to kick off the Rugby Championship.
Cane’s actions came 10 days after England cricketer Jonny Bairstow picked up and carried to the sidelines a protestor who had entered the field of play during the second Ashes test against Australia in London.
Athletes in other codes have also in the past taken physical action to halt the charge of pitch invaders, though few with the vigour of Cane.
The 31-year-old has an otherwise exemplary discipline record. He has yet to receive a red card in 87 tests for the All Blacks or 150 matches for the Chiefs at Super Rugby level.