According to data obtained by corporate investigations firm Kroll Advisory Solutions under the Freedom of Information Act, the regulator had 3,733 tip-offs in the year to May, up 276% from the 994 it received in 2007/8.

Kroll said 18% of the company’s investigations in the past year were started as a result of whistle-blowing.

It blamed the increase on less-stringent controls in overseas markets, the ease of creating fraudulent online identities and better reporting capabilities for whistle-blowers.

The Times reports some campaigners suggest financial incentives should be offered to those prepared to incriminate others.

Last month Bradley Birkenfeld, a former UBS banker, was awarded a record $104m for disclosures that led to the US Internal Revenue hauling in billions of dollars in back taxes and fines from the Swiss bank and its clients.