When Revenue & Customs admitted it had lost a CD Rom containing sensitive financial data this week, it said it was a one-off incident. But to some critics, it pointed to a wider problem.

Chas Roy-Chowdhury of the Association of Chartered Certified Accountants said: "I'm not sure it is OK to say it is a one-off. On the IT side, the Revenue suffers from Murphy's law: if it can go wrong it will."