Spontaneous street parties have been springing up in cities across the world in tribute to the late Michael Jackson.From the Apollo Theater in Harlem, New York City to London, where Jackson was to play a series of comeback gigs, fans celebrated the music and the dance moves. It could be up to six weeks before toxicology tests identify what exactly caused the star’s heart to stop beating. Until then speculation looks set to centre around his reported dependence on prescription painkillers and on his private doctor, Conrad Murray. Murray was with Jackson when he went into cardiac arrest and police have said they will be interviewing him, all the while insisting he is not a criminal suspect. Jackson’s family has collected his body but has not yet released any details on funeral arrangements.