Russian-born City trader named as Britain's biggest taxpayer - The Telegraph

It employs 180 people and also has offices in Paris, New York, Mumbai, Yerevan and Singapore.

Mr Gerko shares the role of chief executive with Zar Amrolia, former currency trader at Deutsche Bank who joined XTX shortly after it was founded.

The businessman has emerged as a public critic of the Kremlin since Vladimir Putin’s forces attacked Ukraine, tweeting that “Nuremberg is waiting” for Sergei Lavrov, Russia’s foreign minister.

XTX sued Mazars for racial discrimination when the accountancy firm refused to work with XTX based on Mr Gerko's Russian citizenship.

In that lawsuit, XTX stressed that Mr Gerko was not subject to any sanctions.

His $6.2bn fortune stems from his 75pc stake in XTX and $2.4bn worth of dividends paid out to him since 2020 by a holding company he controls, according to the Bloomberg billionaires index.

It is understood he has donated to charitable causes including the UBS Ukraine emergency appeal, reading and numeracy initiatives in Africa, a geothermal energy non-profit and the Rewilding Britain scheme.

He is also the founder and a trustee of Mathematics Education for Social Mobility and Excellence (Mesme), which encourages top students at secondary schools to join “maths circles” where they can tackle advanced problems with the help of mentors and peers.

A spokesman for Mr Gerko declined to comment.