Sidney Poitier died of multiple diseases including Alzheimer's, Cancer

Sidney Poiter's cause of death has been released by authorities less than a week before the actor's death.

According to the 94-year-old's death certificate, he died ofheart failure, Alzheimer’s dementia and prostate cancer, obtains TMZ.

A biopsy and autopsy were not performed at the time of his death announcement. He died at home in Beverly Hills on Jan. 6.

The veteran star had earned the honour to be the first black man to win the Academy Award for Best Actor.

Poitier leaves behind his wife of 46 years, Joanna Shimkus Poitier.