Jackson suffering from lung disease?

The author behind a new biography of Michael Jackson has sparked rumours the star is seriously ill - suggesting the singer may be suffering from a deadly lung condition.

Ian Halperin, a former writer for America's Rolling Stone magazine, is producing a new book about Jackson's life and has detailed the singer's medical problems, claiming he is suffering from a condition known as Alpha-1 antitrypsin deficiency, a potentially fatal genetic illness.