Mrs Ruegg, Jonathan's eldest sister, was devastated at the news.
"It was really hard. I was his second mum," she said.
Jonathan lived with Mrs Ruegg when he returned from chef school in Christchurch.
He worked in kiwifruit orchards in the area while looking for work as a chef.
"He ... came up after the earthquake. I was having a baby then. I wanted him to come up. I thought he'd be safe," Mrs Ruegg said, her voice cracking with grief.
The three siblings have since been Skyping and phoning their other siblings based in Australia and parents.
Mrs Ruegg said Jonathan always kept in touch after he left.
"He was really happy when he rang. He rang every few weeks. I don't have a Facebook account so he would always ring me," Mrs Ruegg said, pausing to take a deep breath before continuing.
"We are very close."
Jonathan was known as "Uncle Bono" in Mrs Ruegg's household.
Mrs Ruegg said when her children were young and couldn't pronounce J, "Jono" was transformed into "Bono".
"He lived life to the full. He just had so much energy. It was infectious.
"If you were down he could make you happy just by being in the room. That's why everyone just loved him."
The family have been overwhelmed with tributes and condolences posted on Facebook which Jonathan used regularly.
One of Mrs Ruegg's last memories of Jonathan was when she cooked a celebration dinner for him when he landed his "his dream job" on the Pacific Sunrise.
It was the last time Mrs Ruegg and the other New Zealand-based siblings would see their baby brother alive.
Ben Jackson had come back into reception at Waitomo Caves when he saw six missed calls on his phone.
"I knew something was up because Bex, my other sister, she said 'give me a call now'. I knew it wasn't good. It was terrible."
Ben joked with affection about his brother's lack of singing skill.
"He tried to sing but he was a pretty terrible singer. He was pretty tone-deaf, but that didn't stop him from singing anyway."
Speaking from Australia, Jonathan's parents Michael and Cheryl Jackson told the Bay of Plenty Times yesterday that they were grateful their boy's body was found.
Queensland police told them that if they had not found Jonathan's body when they did, there was little chance it would have been found at all.
"It's sort of positive for us, you know. We've got him," Mr Jackson said.
Mr Jackson said they were making arrangements to bring their son back to New Zealand for his funeral service.
A spokeswoman for the Queensland Police Service said yesterday there were no suspicious circumstances surrounding Jonathan's death and a report had been prepared for the coroner.
