Joni Mitchell reportedly unresponsive after slipping into coma

The 71-year-old folk icon was rushed to hospital last month after collapsing at her home in Los Angeles

A close friend of the musician has filed legal documents to obtain conservatorship over her affairs (AP)

Legendary singer-songwriter Joni Mitchell is reportedly unresponsive and in a coma.

The 71-year-old folk icon was rushed to hospital on 31 March after collapsing at her home in Los Angeles. A day later representatives said she was “awake and in good spirits”, and on 3 April a statement on her official website said that her condition “continues to improve” in the Intensive Care Unit of the UCLA Medical Centre.

On Tuesday, however, TMZ reported that the star has since slipped into a coma, and that her close friend Leslie Morris had filed legal documents to obtain conservatorship over the musician and her affairs.

Mitchell, a stalwart of the late 1960s Laurel Canyon scene, wrote such enduring hits as “Big Yellow Taxi”, “Both Sides Now” and the album Blue. Her last LP Shine was released in 2007.

A lifelong smoker, Mitchell has said that cigarettes “robbed me of my voice”. She also suffers from the little-understood condition, Morgellons Disease, which afflicts victims with irritable, thread-like fibres beneath the skin.