Michael Jackson has announced he is preparing for a comeback world tour, blasting recent reports he is suffering from a deadly lung condition.

Author Ian Halperin sparked rumours the star is seriously ill after telling Britain's Sunday Express this week Jackson is suffering from a condition known as Alpha-1 antitrypsin deficiency (A1AD), a potentially fatal genetic illness.

Halperin, who is writing a new book about Jackson's life, also alleged the Thriller hitmaker is losing the vision in his left eye and even needs a lung transplant after developing emphysema, which can be caused by A1AD.

But a spokesperson for the star is adamant Jackson is perfectly healthy - and is even preparing to step back into the spotlight for a world tour.

His publicist says: "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."