SAOIRSE KENNEDY HILL, the granddaughter of Robert F. “Bobby” Kennedy died as a result of an accidental overdose.
The 22-year-old passed away at the Kennedy family compound in Hyannis Port, Massachusetts in August 1.
The cause of death has been confirmed in a newly-issued death certificate which attributed her death to a toxic cocktail of methadone, alcohol and other prescription drugs including acute diazepam, fluoxetine, nordiazepam and norfluoxetine.
Diazepam and fluoxetine are more commonly sold as Valium and Prozac. Methadone is also most commonly used to treat opioid addiction.
Emergency responders were first called to the compound in the afternoon with Ms Kennedy subsequently rushed to nearby Cape Cod Hospital.
She was pronounced dead at 3:14pm.
A media and communications student at Boston College Ms Kennedy Hill has previously written about her battles with depression.
"My depression took root in the beginning of my middle school years and will be with me for the rest of my life," she wrote in a student newspaper in 2016.
She is survived by her parents, Paul Hill, one of four people wrongly convicted of IRA pub bombings in 1974 who became collectively known as the Guildford Four.
Her mother Courtney Kennedy Hill is the daughter of the former US Attorney General Robert F Kennedy and 91-year-old Ethel Kennedy.
The Kennedy family previously paid tribute to Saoirse with the following statement: "Our hearts are shattered by the loss of our beloved Saoirse."
“She lit up our lives with her love, her peals of laughter and her generous spirit,” the family said.
“[She] was passionately moved by the causes of human rights and women’s empowerment and found great joy in volunteer work, working alongside indigenous communities to build schools in Mexico.
"We will love her and miss her forever.”
See More: John F Kennedy, Saoirse Kennedy Hill