Harry’s story was reported in the Otago Daily Times last weekend.
It detailed how Harry — not his real name — lived in a residential disability service until he "aged out" of care provided by child agency Oranga Tamariki, after turning 18.
After time in Dunedin’s Night Shelter and a motel room, he had tried to kill himself.
He was then moved to Wakari Hospital.
Leaders have described it as "shameful, ridiculous and gut-wrenching" that Harry had been discharged to no fixed abode.
Despite being in Wakari for more than a month, the social worker there had failed to devise a plan for him.
He is in temporary accommodation, where he can only stay a few nights, and has no support during the day.
Dunedin city councillor Sophie Barker called on Oranga Tamariki to deliver care in line with its statement of children’s rights and what Harry needs — a safe place to live and appropriate support.
The children’s rights statement requires Oranga Tamariki to give young people an option to live with a caregiver until 21.
"This is the saddest thing, and a shameful and ridiculous dereliction of human rights," Cr Barker said.
"A place must be found for Harry that meets his needs, whether in this city or in another city."
Oranga Tamariki at the end of August said it was engaged with other agencies in the city to try to provide the support Harry needed, but support has not yet arrived.
City councillor Carmen Houlahan also called for help to be provided immediately.
"It is gut-wrenching.
"Our city should be judged by how it treats people and this poor boy needs help, and sadly probably many more," she said.
"The hope is he is given help now.
"We cannot let him down due to red tape or lack of funding while we plan as a city how to solve our homelessness."
A plan to tackle homelessness, which focuses on the need for co-ordinated, multi-agency work, is being progressed by city council principal policy adviser for housing Gill Brown.
The plan aims to have more people leaving homelessness than entering it, a principle known as "functional zero".
Harry’s electorate MP Rachel Brooking said her office was prepared to provide support to get a positive outcome for Harry.
"I share a deep concern for the wellbeing of this young adult, and I acknowledge the transitional support government agencies and support organisations are trying their best to provide in difficult circumstances.
"My office is prepared to provide whatever appropriate support we can."