Sean 'Diddy' Combs is being sued for reneging on a $55million deal to sell one of his luxury mansions on a star-studded private island in Miami, RadarOnline.com can reveal. The jailed disgraced rapper is currently languishing in a New Jersey federal prison, but had allegedly agreed to flog one of his two side-by-side homes on Star Island to South Carolina-based buyer, John Franklin.