The tax office expects a last-minute dash to its offices today by individuals hoping to declare their offshore affairs before the end of today's amnesty deadline - but those who don't face investigations which begin at the end of March. The Revenue is understood to be collecting details of offshore accounts from more than 300 banks, the FT reports. Permanent secretary for tax, Dave Hartnett, said that a 'growing number' of investigations will begin after HMRC sifts through account details to identify cases in which significant disclosure ought to have been made. HMRC is also set to call individuals to discuss the accuracy of their tax returns, Hartnett told the Chartered Institute of Taxation.