Reform of the film industry funding model is needed to protect workers and eradicate abuse and waste of taxpayers' money, the GMB trade union has said.
GMB regional organiser Denise Walker said the current funding model had created many problems in the industry.
Ms Walker told an Oireachtas committee on Culture, Heritage and the Gaeltacht that the union has become aware of issues of serious concern within the industry.
GMB represents 300 people working in construction, props and driving crews in the Irish film industry.
"Bullying harassment, mistreatment of workers, breaches of health and safety and unsafe working practices, which includes the length of the working day and week," she said.
"No-one has a permanent contract; many have worked in the industry for 20 years yet still have no provision to acquired rights or even a pension."
Ms Walker said those who spoke out for their rights or the rights of their fellow workers were then prejudicing their future employment.
"To challenge the status quo has led GMB activists and members amongst others effectively being blackballed on current productions," she said.
The sector in Ireland is worth an estimated €550million, directly employing 7,500 workers on a full-time basis.
Section 481 tax incentives, which production companies can claim and have helped fund thousands of productions, is currently under review.
"This is an industry which receives millions of euro annually in loans and grants and very generous 481 incentives to create quality employment, yet we see no evidence of quality employment on the ground," Ms Walker said.
She said drivers are regularly expected to work longer than 12 hours a day, breaching current legislation - and that rest periods were often ignored.
She added there were also issues with "bogus self-employment".
"There are many problems with the funding and it has created many problems within the industry," Ms Walker said.
"We welcome ongoing investment in the industry, we want to see the industry grow and prosper, but we would call for serious consideration to the reform of how funding is made going forward.
"This reform must seek to eradicate abuse and waste of taxpayers' monies. As a minimum, proper scrutiny must take place to ensure that funded projects actually create clearly defined jobs and this must be rigorously monitored."