Pop star Michael Jackson is fighting for his life and will die if he does not receive a lung transplant, his biographer has told US gossip magazine In Touch.

Author Ian Halperin said that Jackson, 50, is suffering from the rare genetic illness alpha-1 antitrypsin deficiency as well as emphysema and gastrointestinal bleeding.

Halperin also said the singer could barely speak and was 95 per cent blind in his left eye.