HMRC's specialist High Net Worth Unit (HNWU) has reported a record £220m yield from the UK's most wealthy, up 10% on the previous year's figure of £200m.

The unit - which employs 380 staff across Birmingham, Bradford, Cardiff, East Kilbride, Edinburgh, Portsmouth, Washington and Wrexham - was established in 2009 to focus on collecting tax from the wealthiest taxpayers.

HMRC said that caseworkers rigorously examine potentially inaccurate tax returns from wealthy clients in the course of their focus, resulting in £665m for Treasury coffers over the last four years, HMRC said.

Exchequer Secretary to the Treasury David Gauke said that HMRC's High Net Worth Unit provides the 'specialist attention' they require in ensuring the wealthy pay the tax they owe.

'This government has reinvested almost £1bn in HMRC and expects them to deliver almost £22bn in 2014-15. Since 2010, the unit has raised £582m, increasing its revenue year on year which, at a time when the government is focused on reducing the deficit, is delivering real results for the country,' said Gauke.

HNWU head Martin Randall said that the tax affairs of the richest people in the country can be complex due to large tax bills.

'That's why we've focused resources on getting their tax right. The majority of the wealthiest taxpayers play by the rules, paying the right tax at the right time, but we take action against the minority who don't,' said Randall.