The law firm says there was an 8% increase in the number of cases passed on to HMRC's dedicated evasion referral team by its local offices, according to the figures which reached 2,972 in 2015/16, up from 2,749 in 2014/15.

Fiona Fernie, partner and tax expert at Pinsent Masons, said the increase comes at a time when HMRC is under political pressure to be seen to be effectively tackling aggressive tax avoidance and evasion, with the department allocated  an additional £800m in funding with which to do so as part of the 2015 Summer Budget.

‘Headline-hitting exposés like the Panama Papers leak and the HSBC Swiss banking scandal highlight that sheltering wealth from the taxman remains an extremely highly-charged issue.

This is exacerbated by the apparent blurring of the lines between avoidance and evasion, and the fact that many individuals seem to assume that any type of tax structuring which involves off-shore is automatically illegal," she said.

According to the 2015 Summer Budget, HMRC is expected to recover an additional £7.2 bn in unpaid tax by the start of the next decade as a result of the £800m additional funding, which is to be invested in tackling tax evasion and compliance activities.

It is also expected to triple the number of criminal prosecutions it brings in relation to serious and complex tax crime, to 100 per year within five years.

Fernie said: ‘HMRC is using increasingly sophisticated tools and techniques to uncover wrongdoing – from closer liaison with overseas tax authorities to cutting-edge data analytics which can flag up anomalies or trends within the information that HMRC and other government agencies hold.

This should result in continuous improvements in HMRC's success rate both in identifying suspected crime and prosecuting those cases successfully.’