The song is the first of an expected flood of new music releases by Jackson, who before his death also recorded songs with R&B star Akon and pop singer will.i.am, front man for the hit-making the Black Eyed Peas music group.

Jackson, who died on freshwater pearl ring June 25 aged 50, had spent the previous four months rehearsing in Los Angeles for a gruelling series of 50 concert spectaculars scheduled to begin at London's 02 Arena in July.

More than 800 000 tickets had been sold for the concerts, with organisers promising one of the "most expensive and technically advanced" live shows ever.

Jackson was putting the finishing touches to the show at the time of his death, which authorities in Los Angeles ruled a homicide after cultured freshwater pearl coroners revealed that he had a lethal cocktail of six different drugs in his body.

Video footage from the rehearsals had been intended to help organizers critique the show and was never intended for public viewing. Sony bought the footage for $60m after executives saw only several minutes.

Sony has said an "unprecedented number" of shows across the United States have sold out and other cities - including London, Sydney, Bangkok and Tokyo - experienced similar levels of demand after tickets went on sale in September.

Analyst Jeff Bock of box office tracking firm freshwater perl jewelry Exhibitor Relations said the film could "play bigger than Elvis".