Probes by HM Revenue and Customs (HMRC) into tax avoidance schemes raked in an additional £494 million in income tax for Treasury coffers last year, figures from law firm Pinsent Masons show.

HMRC has stepped up its investigations after several public figures, including actors, musicians, sports stars and comedians, were named as beneficiaries of tax avoidance measures.

Paul Noble, tax director at Pinsent Masons, said: "HMRC has had a number of high-profile wins in tackling tax avoidance, with some of the UK's most famous faces suffering intense public scrutiny for their supposed involvement.

"Returns from investigations have been healthy this year, and HMRC will likely want to build on this success. High net worth individuals and other wealthy taxpayers are likely to face further scrutiny as a result - both here and abroad."

In 2014 a new Counter Avoidance Directorate was created and Pinsent Masons said that it has "significantly sharpened HMRC's abilities to target schemes which it deems are avoidance".

The unit has been given several powers to expedite its work, including requiring upfront payment of the tax under question within 90 days where use of an avoidance scheme is suspected. Payment must be made even before the case has been fully resolved or heard at tribunal, with no appeals process.

A recent HMRC survey of more than 1,000 people found that 63% believed that use of tax avoidance schemes is still widespread. A similar number said that it was "never acceptable" to make use of such schemes.

Almost two fifths of participants said that they felt HMRC is putting "too little effort" into reducing the use of tax avoidance schemes.