The warning follows disclosures from the National Hi-Tech Crime Unit that criminal gangs are threatening to launch denial of service attacks against online bookmakers ahead of next month's Grand National.
Online betting sites have confirmed that they have been hit by denial of service attacks in recent weeks after refusing to pay demands from gangs believed to be operating in Europe.
Miranda Moore, a barrister specialising in organised crime, warned that company directors and employees might be in breach of criminal law if they tried to hide payments to criminals in their corporate accounts.
"You may be breaking the Proceeds of Crime Act. You may also be committing offences under the Theft Act if you mis-describe how money is used in your accounts," she said.