The two-century Shree Siddhivinayak Temple in Mumbai devoted to the Hindu elephant-headed god Ganesha bristles with close-circuit cameras and is guarded by 65 security officers. It is one of India’s richest temples, having amassed 158 kg of gold offerings, worth $67 million, and its heavily guarded vaults are strictly off limits. India is the world’s biggest consumer of gold and its ancient temples have collected billions of dollars in jewellery, bars and coins over the centuries — all hidden securely in vaults, some ancient and some modern. A few years ago, a treasure of ...