Almost a quarter of small businesses in the UK have reported cases of staff fraud in the past year.

A poll by the Bank of Scotland shows 24 per cent of entrepreneurs questioned had caught staff fiddling, with 11 per cent losing up to £1,000 and four per cent up to £5,000.

Although the bank said frauds involving sums greater than £5,000 were rare, it warned small-scale losses could still have a serious impact on profitability.

The results also showed businesses were unafraid to take action against staff who have been conning them.

Almost one in ten said they had sacked or disciplined a member of staff as a result of fraud or theft in the past three years.

This was more common among large companies (21 per cent) than medium (14 per cent) or small firms (seven per cent).

Barry Gardner, of the Bank of Scotland, said all businesses experienced staff fraud but the problem hit small firms harder.

He said: "A loss of £1,000 is far greater to a small business than to a corporate giant.

"While most corporations will have quite sophisticated policies for policing and detecting staff fraud, small businesses probably don't.

"From what we're hearing, it's not life-threatening to a business but normally it's something that owners feel quite strongly about. If their staff are stealing from them, it's more personal."

The survey also found 25 per cent of companies with a male CEO had reported the problem, while only 18 per cent with a woman at the top had.

David Bishop, of the Federation of Small Businesses, said staff fraud was more of a problem in medium-sized companies employing 15 people or more.

He said: "That tends to be the stage where the owner/manager, no matter what they want, starts having to be away from the day-to-day running of the business, into strategic work. That's where the difficulty starts.

"It's a feeling that this company is going to survive whatever I do, whereas at a smaller level, employees are aware that the success of the company is linked to their own."