LOS ANGELES - Folk music legend Joni Mitchell is in a coma and unresponsive, the TMZ celebrity news website reported Tuesday, four weeks after she was hospitalised.
TMZ said a friend of the singer-songwriter - who had been reportedly improving in hospital a few days after she was admitted on March 31 - had filed legal documents to obtain legal guardianship over her.
According to the site, the documents say the 71-year-old singer, one of the symbols of the 1960s Woodstock generation, is "so impaired as to be incapable of being assessed."
Mitchell, whose real name is Roberta Joan Anderson, is known for hits including Big Yellow Taxi, and The Circle Game, as well as her role in the 1960's music scene.
She has received eight Grammys, the top prize in the US music industry and she was inducted into the Rock and Roll Hall of Fame in 1997.
Mitchell has said she suffers from an ailment called Morgellon's disease, which is described as a crawling, biting or stinging sensation all over the body.
The medical diagnosis of the disease is disputed by some doctors who call it a form of psychosis.