The man said the boy was with his parents, brother and twin brother at the home after attending a tangi.
"The boys started getting themselves ready for a walk while the adults enjoyed a cuppa and chat.
"It was at that stage that [one of the boys] came rushing upstairs to tell us that something was wrong with his twin.
"As his mum looked over the balcony, to her horror she saw his legs dangling from the ground as he hung lifelessly with a chain wrapped around his neck."
The man said there was immediate panic and despair as the adults rushed to help the boy.
"[He] was blue in colour and unresponsive as we frantically removed the chain from its hold. There was no breath or life.
"As we battled to bring life back into [his] body, every now and then there would be a glimmer of hope as he desperately tried to gasp for air.
"For the next few minutes [he] continued to move in and out of consciousness and although it seemed like an eternity for help to arrive, members of the volunteer fire service were on the scene within minutes."
The man said it was unclear whether the boy's mind and body would fully recover, however he was alert and cognitively "normal" yesterday.
The incident had been terrifying for the boy's parents.
"It is a difficult thing to describe what it feels like, to watch a child almost die," he said.
"There is a feeling of complete helplessness as you rely on others to bring them back to life."
