Around 20,000 people will have their credit files covertly checked under a tax evasion crackdown, HMRC has revealed.

The pilot programme will see credit reference agencies examine the declared income of individuals against their actual spending patterns in a bid to identify both illegal and legal tax avoidance.

Those deemed to be of interest to HMRC will then face a more detailed probe.

An HMRC spokesperson said: 'We will only use CRA [credit reference agency] data to tackle suspected evasion. The pilot will initially involve around 20,000 people where a risk of tax evasion has been identified.'

While the self-employed that have under-declared their income look set to be the biggest group likely to be rumbled by the pilot, those with offshore accounts or who recently benefitted from an inheritance or a bonus could also be snared.

HMRC was dubbed "too lenient" in a damning report by the Public Accounts Committee which called on the government to be 'more aggressive and assertive in confronting corporate tax avoidance' and ordered HMRC to stop being so lenient with big business.

In its defence, HMRC said it "had recovered £29bn in additional revenues from large businesses in the last 6 years, including £4.1bn in the last four years from transfer pricing enquiries alone".