The 16-year-old was found dead in her bedroom on Saturday morning. A 30-year-old man has been charged with her murder.
Jayden Rush (18) told the New Zealand Herald he arrived at the family home in Corstorphine after midnight on Friday and knocked on his sister's bedroom door but didn't get a response from her.
"I came inside, knocked on Amber's door ... but there was no reply so I assumed she was asleep," he said.
"Not much else happened that night, I just went back to my room."
It wasn't until the next morning that the family went into Amber-Rose's bedroom, and discovered her dead body.
"My mother found her first," Rush said.
"She was screaming, and naturally my reaction was to run in there and try to take over.
"I pulled her away and told her to call an ambulance, so that she'd have something to do, so she wouldn't freak out."
Jayden said he checked his sister's vital signs for a pulse but quickly realised she was dead.
Police turned up shortly after.
"Six or eight of them came and just streamed into her room. And then they just walked out straight away.
Jayden said his sister's death had shattered his mother and stepfather, as well as his older sister who had moved out some time before.
He described his sister as his family's "closest friend" and said she was a soft-hearted girl who was much loved by everyone she met.
"I'm doing what I can to try and lessen the blow," he said.
Amber's mother, Lisa Ann, said on Facebook her daughter's death had "killed her entire life".
"How do I put into words what u mean to me my baby girl, u are literally my other half, my soul, my heart, my everything," she wrote.
A funeral would be held this weekend, though Rush wasn't yet sure of the details.
The man charged with her murder, a Dunedin medical professional, appeared in the Dunedin District Court on Monday and was remanded in custody.
Emergency services have been spotted searching a Dunedin quarry as part of the investigation into the death of Amber-Rose.
Police were yesterday photographed prodding the ground in the pond at Blackhead Quarry with sticks.
The quarry is 4km from Amber-Rose's Clermiston Ave home.
Earlier this week police issued a call for anyone who may have been in the Quarry or beach area between 11.30pm on Friday, February 2 and 12.30am on Saturday, February 3, to get in touch with them.
"In particular, police would like to speak to the occupants of a black Toyota Camry that was in the car park near the pond around this time, and may have witnessed something," Detective Senior Sergeant Rob Hanna said.
Speaking to the Herald on Wednesday, a police spokesman said no update was available regarding the investigation.
A Givealittle page has been set up for the Rush family and by this afternoon $5246 has been donated.
