The fallout from fraud and bribery charges against Indian billionaire Gautam Adani is spilling into the political sphere, as opposition leader Rahul Gandhi calls for an investigation and the arrest of the tycoon. Mr Gandhi has also accused Prime Minister Narendra Modi of shielding Adani. But the ruling BJP is hitting back, by casting doubts on the timing and credibility of the allegations, while also challenging the opposition's accountability. Rebecca Bundhun reports from Mumbai.