Mitchell was taken to UCLA Medical Center on 31 March after she was found unconscious at her Los Angeles home.

According to TMZ.com, she is not responsive to anything and documents submitted by Morris suggest she is "so impaired as to be incapable of being assessed".

Morris hopes to obtain a conservatorship over the legendary singer.

The news is the first update on the folk music legend since a statement on her website suggested her condition was improving.

The note, posted on 3 April (15) read: "Joni remains under observation in the hospital and is resting comfortably. We are encouraged by her progress and she continues to improve and get stronger each day."

The cause of the singer's health scare has still not yet been made public.