"The fraudster is often the person you least expect," he said.
Mr Rowe said no business was immune from the threat.
This was particularly so with small outfits whose owners were often too busy running the business to effectively focus on managing their internal auditing.
"When it comes to following up on criminal history background checks or checks on CV referees, some employers seem prepared to go with their gut instinct rather than doing basic checks and proper due diligence.
"It's unfortunate because it leaves them vulnerable.
"It may start with the theft of a very small amount of product but if someone is given the opportunity the person can rationalise it and become greedy and take more and more."
Mr Rowe said at one business he dealt with, the amount of office stationery that had found its way to trusted staff members' homes was "unbelievable".
Another example was a Bay of Plenty bar where staff served large numbers of free drinks to friends and associates "right under the nose" of the owner working alongside them.
In another case, an employer engaged extra security staff to try to stamp out large-scale theft only to find it was the security staff who were ripping the business off.
"Unfortunately lots of victims won't go to the police, either due to embarrassment or because they don't want to show their competitors they failed to do the required due diligence and failed to pick it up sooner," he said.
Mr Rowe said investigating employee fraud complaints was labour intensive, and some cases could take up to six months to complete, which often resulted in an extra cost to the victim.
In his experience given police limited resources, these types of cases were given lower priority than violent and sexual offending complaints and, therefore, took some time to resolve, he said.
Twyford & Associates director Arthur Twyford agreed with Mr Rowe that more than 50 per cent of businesses would be victims of fraud "at some level".
Mr Twyford, who is also a former police detective, said that included employees stealing time and then going onto stealing products or services.
He cited the example of a staff member who started by stealing a packet of cigarettes.
When the investigation was completed, tens of thousands of dollars of fraud had been uncovered.
Mr Rowe and Mr Twyford urged victims to always report these crimes to police, as the complaint would appear on police records to help safeguard future employers.
Western Bay area commander Inspector Clifford Paxton said he was unable to provide figures in relation to the number of current cases of employee fraud under investigation in this district, because fraud was a "broad category" and there was no specific crime category for staff fraud.
It would take substantial research to establish the percentage breakdown of all fraud cases relating to employee fraud, he said.