Former Chairman of Railway Recruitment Board, Mumbai S.M Sharma and his son are among 15 persons charge-sheeted by Central Bureau of Investigation for their involvement in a railway recruitment scam. The charge-sheet was filed in the court of special judge for CBI cases in Hyderabad today. The scam involved leakage of the question papers for Assistant Loco Pilot and Assistant Station Master examinations held in the month of June this year.According to CBI, the accused have been charge-sheeted for alleged criminal conspiracy, cheating, illegal gratification and causing disappearance of the evidence. A CBI release said the case was registered on the 15th of June this year and the investigation was completed in 89 days.