The public sector, which is experiencing a high demand for skilled IT professionals, is particularly at risk of attracting rogue contractors looking to pick up lucrative work, said Parity Resources.
"A contract cowboy is someone who job-hops and does not necessarily deliver on the client's expectation. They constantly chase contracts, leave them mid-term and lack integrity," said Alan Rommel, director of corporate accounts at Parity.
Some freelance staff have a reputation for switching between agencies to increase their rates, rather than focusing on the job in hand, said Parity.
Paul Carratu, managing director of corporate investigation company Carratu International, said rogue IT contractors posed a real threat to businesses. "The results can be horrendous. You are giving them the keys to your door. They can sell your information to the highest bidder.
"We have known situations where they have taken client databases and development products they have been working on. One stole a database and sold it to the competition," he said.
Parity said employers and IT recruitment companies need to improve their candidate screening and carry out thorough reference checks.
Jeff Brooks, chairman of recruitment industry lobbying group the Recruitment and Employment Confederation, IT sector, said too many employers were taking shortcuts when hiring staff.
"There are certain steps that you would expect a good staffing company to take, but in the rush to get staff onto a project, too many suppliers and employers frequently cut corners. The price paid in the long term is significantly higher than the time needed to do it right first time around," he said.
Carratu said, "You need to know where the contractor has worked before, check they are competent and tighten up your controls."