Mariah Carey's sister has begged the singer to fix their rift and save her life after she was left with mounting medical bills.
Alison Carey - who is a recovering drug addict and HIV-positive - suffered brain damage after a terrifying home invasion attack in New York last April, and despite surviving the near-death experience, she is left requiring life-threatening brain and spine surgery.
Mariah - who is estimated to be worth US$510 million - and her sister had a massive argument in 1994 and have barely spoken since, but the mother-of-four has released a video to Daily Mail Online pleading with her sister, whose boyfriend James Packer is estimated to be worth US$4.7 billion, to help her out.
In the clip, she says: "Mariah I love you, and I desperately need your help, please don't abandon me like this."
Mariah and Alison's brother Morgan Carey has also called on the We Belong Together hitmaker to help save the former prostitute, who suffers from seizures, memory loss, and occasional loss of consciousness due to severe brain damage.
Speaking to the publication, he said: "Because Mariah has not found it in her heart to help Alison get the care she requires there are times when Alison forgets or is unable to take her medication and this sometimes precipitates problematic behaviour.
"Mariah is the one person in the family who could actually make a real meaningful difference to Alison's life. The least she could do is put Alison in a good hospital and make sure she gets the care she needs.
"We're talking about small change to these people, her fiancé is a billionaire."
However, a representative for Mariah insists the singer has spent "hundreds of thousands of dollars" on her sibling.
They said: "Through the years, Mariah has spent hundreds of thousands of dollars supporting Alison and her children.
"In fact, Mariah has supported her extended family for over two decades."
Alison - who Morgan says inherited US$1.6 million from her father Alfred Carey after his death in 2002 - was recently released from hospital and attends drug addiction meetings to help keen her clean, but is due to have surgery on her spine and brain.
Last July, Alison claimed she was being kept in hospital as a patient for a serious head injury against her will, three months after the mysterious attack at her home.
Alison, who was admitted to a Long Island psychiatric ward at a hospital in New York City, said at the time: "I need a lawyer to get me out of this hospital because there is no reason to keep me in here for three months ... Please tell Mariah to get me out of here! She must know what's happened to me! I want out!"
Alison has been admitted to the facility before and was a confirmed patient there in 2012.
- Bang! Showbiz