The average UK citizen could be $30,000 (£21,000) better off by 2020 than they are today if Britain voted to leave the EU, research by New World Wealth (NWW) has claimed.

In a note out today, the wealth intelligence group estimates that the average wealth per person would rise from $147,000 to $180,000 by 2020 if a Brexit went ahead.

However, its expects this figure to drop to around $140,000 if Britain decided to stay.

NWW's founder and head of research Andrew Amolis argues that the UK, like Australia, would have a hard border and therefore it would be able to restrict immigration.

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He explains: "High immigration levels bring down average wages due to demand and supply dynamic, which in turn brings down average wealth per person. Uncontrolled immigration can also put pressure on healthcare and social security systems."

Amolis adds that a Brexit would also allow the UK to bring taxes down and free it from EU regulations, which restrict growth of its financial services, hi-tech and manufacturing sectors.

"Over the longer term, a Brexit will result in greater ties with former English speaking colonies such as Canada, USA, Australia, India and New Zealand, all of which have much stronger economies than EU countries. The UK is the only English speaking country in the region, which is a major advantage when dealing with these countries," he said.

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Australia has adopted a restrictive immigration policy over the past 15 to 20 years, keeping its population relatively small and only admitting skilled migrants, based on a points system, NWW explains.

As a result, Australia’s average wealth per person has gone up by 250 per cent from $59,000 in 2000 to $204,000 in 2015. Over the same period, the average UK person's wealth has gone up by only 58 per cent from $93,000 in 2000 to $147,000 in 2015.

"It is our view that a Brexit will benefit individual wealth creation in the UK," Amolis said.