The Serious Fraud Office on Monday urged City workers to turn whistleblowers in the fight against financial crime.

It has posted a special form on its website allowing workers in the financial services industry to report bad practices. The form invites them to say how much money is involved — pointing out that the SFO usually only investigates cases involving more than £1 million — and asks for details of how the fraud was perpetrated, what happened and the people and companies involved.

It also asks whistleblowers to say whether they suspect that large numbers of people have been defrauded and whether they have documentary evidence to support their allegations.

Richard Alderman, the SFO director, said the department was specifically targeting individual workers, ex-employees and shareholders. He said: “What we've found is that, at times of market turbulence, fraud is discovered. We find out what's been happening as a result of turbulence in the markets and we also find there are opportunities for more frauds.

“We would like to hear from people who have got evidence about those frauds. They could be investors or people who have worked in any of the institutions that have been involved. We're also very interested in victims.”

He said that the SFO had also written to senior and managing partners of London's leading accountancy and legal firms asking them for information on detecting fraud

The move follows a trip by Mr Alderman to the United States in which he met officials from the Department of Justice and the FBI — which have both been using this technique for some time.

Mr Alderman said that, in looking for frauds arising from the credit crunch, the SFO was working closely with law enforcement agencies here and abroad. He added: “We're also interested in mass-marketed types of fraud, such as boiler room activities and mortgage fraud.”

One of the most high-profile cases successfully pursued by the SFO in recent years was a direct result of a company insider blowing the whistle on fraudulent activity. That case saw Severn Trent plead guilty earlier this year to two charges of providing false data on leaks to Ofwat, the water industry regulator.

A spokesman for the SFO said the new initiative had already brought matters to the department's attention which it might otherwise not have heard about. He admitted that the SFO was aware of the potential for people to report co-workers or former colleagues maliciously. He added: “We do have to be careful. When people are laid off, sometimes, they do want to throw muck around.”

He said that unlike the DoJ, the SFO would not be able to offer immunity from prosecution to someone blowing the whistle on a scam in which they had taken part.

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