The singer announced on Tuesday that both her mum Patricia, 87, and her sister Alison, 63, died on the same day this weekend.

Now it's been revealed that Alison was in hospice care for the weeks before she died but Mariah "never tried to contact" her older sister even after she'd been put in hospice care.

"Alison was on home hospice care for the last three weeks of her life," her friend Dave Baker told The US Sun, adding that she had "a problem with internal organs."

"A phone call or, better still, a video call (from Mariah) would have meant so much to Alison. But it never came," he said, adding, "The callous rejection added more hurt to Alison's pain. She talked about it frequently. She wondered if Mariah or any of her relatives would come to her funeral."

He continued, "Beneath a tough exterior Alison was a highly intelligent, warm, and sensitive person. I have known her for nine years and as her friend, and in recent months her carer. I will miss her greatly."

He added, "Farewell Alison. May you now find peace, your tortured soul forever free from earthly pain."

TMZ has reported that Mariah spent the week with her mother Patricia before she died.

The siblings had been estranged for years. It's believed Mariah tried to support Alison financially and emotionally but she could never beat her addiction issues.

The Hero singer, 55, wrote about her sister in her 2020 memoir, The Meaning of Mariah Carey. She claimed Alison once "drugged me with Valium, offered me a pinky nail full of cocaine, inflicted me with third-degree burns, and tried to sell me out to a pimp."

Alison denied the claims after the book was released.