There has been a startling rise in personal and account data being stolen from UK companies, according to the Cifas, an anti-fraud advice body.
It recorded a 63 per cent rise in staff members stealing customer data in 2010 compared with 2009. Cifas adds that many such cases may go unreported.
"Much attention is given to the dangers posed by criminal gangs operating in the world of cyber hacking. The dangers of staff fraud, however, are just as real, both financially and in terms of reputation. This reputational risk may explain the reluctance to report cases to the police," said Arjun Medhi, Cifas's staff fraud adviser.
Younger staff are involved in a disproportionately high percentage of fraud cases detected. The report said that 29 per cent of staff fraudsters are aged under 21, compared with only 3 per cent aged 41 to 50 with not one instance aged over 50.
Ms Medhi adds that many of the fraudsters have been recruited by criminal gangs, others look to grab data in the hope of selling it to criminals later.
Anti-fraud campaigners have urged consumers to be careful when dealing with companies, stressing the need not to give away personal information.