Mariah Carey’s older sister has sent out a “desperate” plea to her sister in the shape of a video, with the hopes to gain support from the singer who is estimated to be worth around $535 million.

Alison Carey is a former prostitute who in the past year endured a home invasion that left her brain damaged and seriously ill. Alison is also HIV positive. Amid mounting medical bills, desperate Alison awaits further life-threatening brain and spine surgery and if she pulls through, faces years of physical rehabilitation.

Mariah’s and Alison’s brother, Morgan Carey says that, ‘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.

A representatives for Mariah denies the claim that she has not helped her sister. ‘Through the years, Mariah has spent hundreds of thousands of dollars supporting Alison and her children,’ the rep told Daily Mail Online. ‘In fact, Mariah has supported her extended family for over two decades.’

Morgan says Alison inherited $1.6million from her father Alfred Carey, when he died in 2002, and she set up trust funds for her children.

The rest of the money she has squandered on her drug addiction.

Should Mariah cover her sister’s medical expenses despite what’s happened in the past?