Police on Friday arrested four members of a single family for their alleged involvement in black marketing of petrol, taking advantage of the current fuel crisis. Niksan Gauchan along with his wife, brother-in-law and mother-in-law were arrested from Bhotebahal, KMC-21. Police deployed from Janasewa-based Metropolitan Police Circle  arrested Gauchan (34) acting on a tip-off about the availability of petrol in his Gauchan Store. It was reported that he was selling one litre of petrol for at least Rs 650. Gauchan is the permanent resident of Turan-1 of Gulmi district. Police have arrested his wife Sita Gauchan (30) for her involvement in facilitating the transaction of petrol. His mother-in-law Kalpana Tulachan (52) would supply petrol to Niksan while his brother-in-law Sudesh Tulachan (25) of Kalikanagar of Butwal Sub-Metropolitan City-13 was involved in dealing with the customers, police claimed. Before arresting them, the police had approached them as customers. The Gauchan family had declined to give petrol for less than Rs 650 per litre. After police in civil uniform offered the cash equivalent to 20 litres, they had only agreed to sell the fuel. Police confiscated 20 litres of petrol and cash receipt from the suspects. Police said that necessary investigation is underway.