The security company, Allied Security, is being investigated after it was accused of encouraging its staff to cheat in getting an NZQA qualification.
Staff completing a level two training assessment were emailed copies of suggested answers and told to put them into their own words when filling out assessment booklets.
Two staff members complained to their union and provided copies of the emails.
A spokesperson for the Unite union, Barry Sutherland, says the company has said it was a misunderstanding.
But Mr Sutherland says Allied Security may have been motivated by government subsidies it receives for each NZQA credit awarded to its staff members.