Engineering group Monadelphous says it is continually reviewing and refining internal controls over worker conduct, following the jailing of a former employee for fraudulent activity over four years.
The trial of Bruce Alfred Little in Gladstone, Queensland has shone a light on an alleged practice of employees being assigned by superiors to do personal work under a client's account.
The court also heard allegations of project managers transferring labour costs from the contract of one client to another.
Mr Little was jailed for at least 14 months on Friday for misusing an estimated $52,000 in Monadelphous' assets and employees' labour to make improvements at his property and do work on motor vehicles.
The former project manager had the work carried out between 2006 and 2010 under a contract with alumina refinery operator Queensland Alumina (QAL), the Gladstone District Court heard.
According to reports by the Gladstone Observer, former Monadelphous workers told the court that from time to time they were asked to do "foreigners" - jobs for the personal benefit of colleagues.
In addition, former employee Adrian Bubb said he had seen labour costs transferred from less-profitable Monadelphous jobs to more profitable ones.
Crown prosecutor Melissa Wilson told jurors that Mr Little had used funds left over from a QAL job to carry out the works on his property, the Observer reported.
In sentencing Mr Little to a maximum three years' jail, Judge Leanne Clare said he had been deliberately dishonest and shown no remorse for his actions.
"The way in which you flagrantly abused that trust was breathtaking," she was reported as saying.
Monadelphous general manager human resources Philip Trueman said the company took seriously its commitment that employee behaviour reflected the highest standards of conduct.
"We have a robust system of internal controls, which is regularly reviewed, internally and by our external auditors, to ensure that these standards are maintained," Mr Trueman said.
"These controls are supple- mented by processes, which are continually refined, aimed at identifying and reporting any potential breaches."
He said Monadelphous was proud of its long-standing relationship with clients and was committed to continually improving them.