Chinese banknotes
Chinese 100 yuan banknotes in a counting machine. Research shows that $1.2tn in capital flight have left countries like China and Russia to offshore havensReuters

As David Cameron gets set to host a global anti-corruption summit, it has been revealed that more than $12tn (£8tn) has been siphoned from emerging economies such as China and Russia into offshore accounts.

In the wake of the Panama Papers findings into tax havens, the research by Columbia University professor James Henry for the Tax Justice Network has shown $1.2tn from China is stashed overseas and $1.3tn of assets from Russia were sitting offshore.

He found that among the worst-affected countries are Malaysia, Thailand and Indonesia which have had corruption scandals recently. Also, oil-rich countries like Nigeria and Angola, Brazil and Argentina were sources of considerable capital flight.

Henry told the Guardian: "It's like the Star Wars scene: you have the tax dodgers in one corner, the arms dealers in another, the kleptocrats over here. There's also those using tax havens for money laundering, or fraud."

His figures follow an 18-month investigation and came from compiling and cross-checking data from institutions like the International Monetary Fund and the United Nations.

Henry said those using tax havens to guard their money were exploiting the legal and financial systems of other countries. "All of these felons and kleptocrats are, in a way, essentially dependent on the rule of law when it comes to protecting their money," he said.

On Thursday (12 May), London will host an anti-corruption summit at which the TJN is urging Cameron to push a crackdown on those who ease financial secrecy. It also calls on all politicians to make their personal financial situation transparent.