Lloyds TSB is to install software to protect against employee fraud in its retail banking business.

The system, from Actimize, will analyse employee behaviour against multiple data sources and examine data for expected and unexpected patterns, similar to techniques used in law enforcement.

Banks are increasingly concerned about insider threats. A recent global survey of seccurity professionals commissioned by Arcsight found that nine out of 10 respondents regarded insider threats as one of their top three security concerns.

'We pride ourselves on our ability to protect our customers from all types of threats, no matter where they come from,' said Bob Spencer, head of group financial crime at Lloyds TSB.

'The system reinforces the bank’s investment in securing both customer and Bank assets.'

The City of London police estimates that one third of its cases now have an insider element to them.