Jamie Lee Curtis' sister Kelly's cause of death shared as details on final days emerge

The cause of Jamie Lee Curtis' sister Kelly's death has been confirmed by the Blaine County coroner's office.

Posting a throwback photo on Instagram with fellow actress Kelly - famed for her roles in Magic Sticks and The Devil's Daughter - the Halloween star announced her passing on 30 May, aged 69.

"A warm aloha to my older sister, Kelly Lee Curtis," Jamie penned in the caption. "She passed away this morning. In her home. In nature. At peace.

"She was my first friend and lifelong confidant. She was jaw-droppingly beautiful and a talented actress. She played a mean game of hearts, collected turtles, loved her family, nature, music, thrifting, travel, Facebook, and Pokémon Go."

Jamie continued: "She was proud of her Danish roots and Hungarian Jewish ancestry and was a devoted American patriot."

The 67-year-old opted not to disclose the cause of her sister's death in her statement. However, the Blaine County coroner's office in Idaho has since confirmed that Kelly passed died of natural causes.

Jamie did, however, confirm that Kelly had passed away in Idaho, where the pair moved from Los Angeles as children, along with their stepfather.

"She will be remembered for her loving generosity, fierce opinions, endless curiosity, unique style, and her powdered, almond, crescent cookies at Christmas, hence her name, Auntie Cookie," Jamie continued. "Kelly always signed off any message or fare thee well with a Hungarian blessing…

"Isten Veled, God is with you. Isten Veled to my sister of the sun and the moon, my Tai. I'll see you on down the line."

The Blaine County coroner's office also provided an insight into how Kelly spent her final few days, sharing their report with US Weekly.

She'd been in hospice care for several weeks during the lead-up to her death at 2.30am on 30 May. The coroner added that Kelly's husband, John Marsh, had been at her side when she passed.

It hasn't yet been confirmed whether Freaky Friday star Jamie and other family members had been there at the time.

The Curtis' have since expressed wishes to have Kelly's body cremated.

The report didn't confirm whether an autopsy had been requested.

Following the initial announcement of Kelly's death, Jamie also shared a series of black-and-white professional photographs, taken by Suzanne Tenner, showing the sisters together on the eve of her wedding to her husband, Christopher Guest, in 1984.

She wrote in the caption: "In 1984, on December 17, in the evening before my wedding, my sister, Kelly, who was my maid of honour, came to my apartment and slept over. Our friend, Suzanne Tenner, came and made a portrait of the sisters before I got married.

"She sent me this contact sheet today in condolence for the loss of my beautiful sister."

Reflecting on childhood memories, Jamie continued: "My sister and I were close as children but also had that sibling competition for divorced parents' attention and love, and we were wildly different and lived apart for many years, but she came back to be with me at my wedding and never really left again.

"She worked for me at one point when she was in between jobs as my as-sister-aunt and became an integral part of my family structure. I miss her today but am buoyed by the knowledge that she is at peace."

If you have experienced a bereavement and would like to speak with someone in confidence, contact Cruse Bereavement Care via their national helpline on 0808 808 1677.