Did the CBI, on the eve of Karnataka election, help rescue the Reddy mining barons of Ballari who are today key candidates and campaigners for the BJP? The matter dates back to 2013 when the Karnataka government handed over a host of cases of illegal export of iron ore from Ballari. A number of mining companies were found to have broken the rules, including the companies of Janardhana Reddy. The charges pertained to ore being illegally exported from nine ports, in four states, but by end last year, the CBI began to close the cases, in state after state. The exact reasons why remain unclear, until now. Tonight on Reality Check, NDTV exclusively reveals those reasons - the set of letters which show that Reddy brothers got reprieve not due to lack of evidence but due to technical reasons.