Credit: Jason Merritt/

The Los Angeles County Department of the Coroner's has released a brief statement regarding the shocking Jan. 4 death of heiress Casey Johnson at age 30.

The coroner has determined that Johnson -- who suffered from diabetes -- died of "diabetic ketaocidosis." While some suspected foul play or a drug overdose when the hard-partying Johnson passed away, the coroner had then stated that the cause of death was "natural."

An heiress to the Johnson and Johnson fortune and allegedly engaged to reality star Tila Tequila, Casey was found dead in her L.A. home last month.

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She was laid to rest at her family's estate in New Jersey on Jan. 12. Casey is survived by Ava, her adopted three-year-old daughter; Ava is currently in the care of Sale Johnson, Casey's mother.

The full autopsy report should be available within the next two weeks, the coroner's statement notes.