Using its proprietary database of global UHNW individuals, the firm estimates there are 4,960 NRI individuals worth a combined $465 billion in assets including shares in public and private companies, residential and investment properties, art collections, planes, cash and other investables.

A geographical breakdown shows that around 39 per cent of ultra-wealthy NRIs live in North America, while Europe and North America together account for approximately 60 per cent of the market – or 3,000 individuals.

Meanwhile, the aggregate wealth of UHNW Indians is roughly twice that of the ultra-wealthy non-resident community, at $945 billion. At the top end of the wealth scale, there are 135 Indians worth between $500 million and $750 million, and 215 Indians in the $250 million to $500 million range. The equivalent figures for NRIs are 80 and 130.

"Despite the total wealth of India's UHNW population being… higher , about 38 per cent of the world's UHNW Indian individuals do not reside in India," said David Friedman, executive vice president of strategy at Wealth-X.

"Private wealth and asset managers seeking to increase their assets under management must not overlook the expansive and highly interconnected community of ultra wealthy NRIs," he added.