New Delhi, April 21 -- Four days after four members of a businessman's family in Delhi's Golf Links were held hostage and gold worth Rs.25-30 lakh looted, Delhi Police on Monday said the robbery was an inside job involving the victim's current and two former domestic helpers. Three of the accused, including a former staffer, have been arrested. Delhi Police said they have arrested the alleged mastermind along with two others from Mumbai and Uttar Pradesh's Kasganj. Guddu Kumar Kamat (35) and Raman Kamat (35) were picked up in Mumbai, while Amit Singh was arrested during raids in Kasganj. Raman had earlier worked as a domestic staffer at the victim's house. Police said Guddu is the mastermind of the robbery. He had asked Rahul, Sushil and Ra...