Police have confirmed Horst Westenfelder, 64, died overseas in July, bringing the number of people who died as a result of the eruption in December last year to 22.
Whakaari / White Island erupted on 9 December 2019 while tour groups were still on the volcanic Bay of Plenty island.
Westenfelder died due to medical complications while receiving treatment for his injuries in a hospital overseas on 2 July.
Police released a statement from his wife Angelika Westenfelder and family saying it was an irreplacable loss.
"Our lives have changed! It is unbelievable, how many months my joyful, sensible and strong husband "Horsti", was fighting for his life and I am thankful to everyone who was thinking of us and helping us during that very hard time.
"He lost this battle and started his last journey in July. It is an irreplaceable loss for our family, his friends and of course for myself.
"In loving memory of a full and exciting life. I will always miss you."
A public remembrance event marking one year since the eruption will take place at Mataatua Reserve from 11.30am on 9 December.
Ngāti Awa will host a small-scale remembrance event for families most affected by the tragedy, invited representatives of emergency responder groups and envoys of overseas families who are unable to travel.