Officials of the Hyderabad Commissioner’s Task Force, Shamshabad Zone, busted the gang with the arrest of four persons on Monday evening. Police said that Mohammed Munawar, a two-wheeler mechanic, was the mastermind of the racket. They all pretended to be treasure hunters who could turn coal into gold, and find gold buried in barren lands as well as underneath buildings,’’ an official said. At least 11 people paid Rs 1 crore in total to Munawar and his gang on the promise of turning coal to gold, said police. After digging the ground, the gang planted a sack containing coal along with duplicate gold-coated coins, said police.