The two head constables had detained three persons — Deepak, Bunty and Rahul — for allegedly collecting fund (chanda) for organising a bhandara (mass feast) using fake receipts, said the officer. The head constables allegedly demanded `50,000 for their release when Prakash went to negotiate with them. Finally, they settled on Rs20,000. Prakash paid Rs8,000 and got two of the detained persons released while Rahul was held back by the accused policemen till the remaining Rs12,000 were paid, the officer said.