City of London police are investigating 10 huge frauds with losses totalling half a billion pounds including an alleged scam involving the hijacking of a ship.
The cases are among 708 major live inquiries being conducted by detectives after an explosion of online fraud across the UK.
City police Commissioner Ian Dyson said Action Fraud, the national fraud reporting body, was now receiving about 40,000 reports of scams every month.
He revealed how the biggest 10 cases involve 4,580 victims across the UK.
One case involves around 450 retired and serving Gurkha soldiers who are feared to have fallen victim to a suspected £50 million Ponzi scheme.
Another inquiry centres on allegations of deception over claims that a cargo ship was hijacked by pirates off the coast of Yemen.
Other investigations with alleged multi-million-pound losses include an inquiry into an alleged City insider trader who is claimed to have racked up losses of £4 million and other complex deals to do with land banking and carbon credit fraud. Mr Dyson, who was appointed in January, revealed that the perpetrators of 50 per cent of all fraud reports were based in foreign countries and could not be touched by law enforcement.
He said: “We cannot investigate our way out of this, it is global and it is online. The perpetrators in about 50 per cent of the frauds we receive each month are abroad. They don’t even need to be people, they can be websites, they are call centres, so it is unrealistic to think we can lock someone up in the traditional way for every crime.”
In an interview with the Standard, Mr Dyson said specialist fraud investigators were tackling crime gangs with links across the world.
When police could not arrest foreign offenders, officers focused on disrupting their activities by closing down tens of thousands of websites, phone lines and bank accounts each year.
He said detectives were supported by around 30 civilian experts who were on secondment to City police, including specialists from Microsoft, the insurance industry and the Treasury.
Mr Dyson said: “There can be a perception that it is Pc Plod trying to track very sophisticated online internet savvy fraudsters. I want to address that. I have got very tech-savvy people working for me, whether they are police officers or people on secondment from other industries or other agencies.
“I also want to address the perception that fraud is so big and so global that people think if they report it to the bank nothing ever happens and law enforcement is not interested. Well, we are interested. It is just educating everyone that you cannot get a collar felt for every crime that is occurring.”
He predicted the Crime Survey for England and Wales would record five million extra offences when it includes fraud in its July figures for the first time. Mr Dyson said law enforcement was fighting back with the launch of the Home Office-funded Joint Fraud Task Force and an alliance between his force and the Manhattan District Attorney’s office.