A major scam aimed at hundreds of internet banking customers has been averted, the UK's new Serious Organised Crime Agency (Soca) has said.
Soca has promised to look at large-scale organised fraud
The unit, launched in April, prevented the fraud - targeting account passwords and names - by issuing a new style of alert to financial institutions.
It led to an arrest in a foreign country, said Soca boss Bill Hughes.
Soca, which has been dubbed the UK's FBI, brings together 4,000 police, customs and immigration experts.
"We became aware of an act that was about to be aimed at internet banking," said Soca director-general Mr Hughes.
"We arrested the person outside the jurisdiction with the help of our partner agencies overseas."
One of Soca's predecessors, the National Criminal Intelligence Service, issued similar alerts but Mr Hughes said his organisation had a closer relationships with business and had developed the system of alerts.
Warnings can be made in writing or on CD, and in urgent cases Soca - which is not revealing details of the current case - would telephone banks to issue an alert.
Soca amalgamates the National Crime Squad, the National Criminal Intelligence Service (NCIS), and investigators from Customs and the Home Office's Immigration Service.
At its inception it was thought that Soca would be taking a hands-off view towards fraud - but has since promised to devote at least 10% of its time and resources to large-scale organised fraud.
Soca chairman Sir Stephen Lander said: "This was the first major one. It is a good example of prevention being better than cure.
"It is about using information in an active way to get ahead of the criminals."