Describing the demonetisation exercise of the Modi government as the "most ingeniously designed official money laundering scheme", former Union finance minister P Chidambaram on Thursday said the ban did not render any currency notes "worthless" and the government "did not reap a bonanza of Rs 3-4 lakh crore."All the demonetisied notes, actually, 99.3 per cent, were returned to the RBI, said the senior Congress leader."Practically every single currency note was officially exchanged at bank counters," he said."It was the most ingeniously designed official money laundering scheme. Who knows it better than you in West Bengal who had witnessed deposits of large sums of cash barely hours before demonetisation was announced," Chidambaram said.He also said the demonetisation did not put an end to fake currency and to generation or use of black money and the consequences of the move have been catastrophic."Miscreants successfully counterfeited the new Rs 2000 and new Rs 500 denomination notes.""Demonetisation did not render any currency note worthless. And the government did not reap a bonanza of Rs 3 lakh crore to Rs 4 lakh crore..."Millions of people were pushed into debt, millions lost their jobs, thousands of MSMEs were shut down and over a hundred people died while standing in queues. The GDP growth fell by 1.5 per cent," he said.