Michael Jackson has hit back at claims that he is battling a deadly lung disease by insisting he is busy preparing for a world tour.

Author Ian Halperin sparked rumours the star is seriously ill after telling the UK press Jackson is suffering from a condition known as Alpha-1 antitrypsin deficiency (A1AD), a potentially fatal genetic illness.

Halperin is writing a book about Jackson's life and claims the King of Pop is losing sight in one eye and desperately needs a lung transplant.

However, in a statement, his publicist has strongly refuted the claims, saying: "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 unauthorised 'biography.'

"The writer's wild allegations concerning Mr Jackson's health are a total fabrication. Mr Jackson is in fine health, and finalising negotiations with a major entertainment company and television network for both a world tour and a series of specials and appearances."

See Jacko through the years below