More than 40 per cent of companies fail to check staff activity regularly and almost half do not train staff in awareness of fraud, according to a survey by PA Consulting on computer-related fraud.
The survey shows that fraud is costing British organisations up to £10bn a year - half through mis-use of computer systems and often perpetrated through collusion between an employee and others inside and outside the company.
Peter Jenner, a director of PA, said the fraud amounted to "a parasitic industry with an income of £40m per day in the UK".
The important problem was with management's lack of control rather than with the computers themselves, he said.
Few seemed to realise that there were computer systems available that tracked patterns of behaviour within various parts of an organisation and flagged up anything that might expose the company to risk.
Mr Jenner added: "We know too little about the Baring Brothers' problem to comment, but if they had had this kind of information six months ago they could have implemented things to stop it happening.
"It is clear from our survey that management control is the real problem - much more than any technical security problems with computers. Management control is lousy," he said. The report shows that almost two-thirds of fraud cases are discovered by chance rather through formal detection processes and that more than half the companies surveyed have never assessed their exposure to fraud.
This is in spite of 80 per cent saying that it is now a serious problem and that it will get worse.
Already losses due to known fraud average £5.2m each year among the companies in the survey. Mr Jenner said that would-be fraudsters were having to collude with others to succeed as business processes and the computer systems used became more complex.
There was growing concern that collusion with people outside a company was based on organised crime and that people were increasingly being "planted" inside target firms.
PA also warns that companies must detect fraud within a week at the outside if they were to have any chance of recovering the money.
However, the survey shows that it normally takes six months to uncover any problem - long after the assets and the fraudsters have disapppeared.
The report shows that fraud is rarely the result of computer hackers but instead due to exploitation of weaknesses in everyday transactions.
"The difference is that computers have vastly speeded up the way fraud occurs and changed the method fraudsters use," it says.Reuse content