In his new book about Michael Jackson's life, author Ian Halperin has made some serious allegations about the King of Pop's health.

The former Rolling Stone writer is claiming that Jackson suffers from a condition known as Alpha-1 antitrypsin deficiency, a potentially fatal genetic illness [via Gigwise.com].

In Alperin's words, "He has had Alpha-1 antitrypsin deficiency for years, but it's gotten worse. He needs a lung transplant but may be too weak to go through with it. He also has emphysema and chronic gastrointestinal bleeding, which his doctors have had a lot of trouble stopping. He can barely speak, the vision in his left eye has 95 per cent. For years Michael has been working with doctors to make sure it doesn't progress. He has been on medications that have stabilised him."

Update: In a statement issued late yesterday, Jackson's "official and sole spokesperson," Dr. Tohme Tohme, said the following: "Concerning this author’s allegations, we would hope in the future that legitimate media will not continue to be exploited by such an obvious attempt to promote this unauthorized ‘biography.’ The writer’s wild allegations concerning Mr. Jackson's health are a total fabrication.  Mr. Jackson is in fine health, and finalizing negotiations with a major entertainment company and television network for both a world tour and a series of specials and appearances."