Unions representing workers in the film industry have said issues of bullying, harassment, mistreatment of workers, breaches of health and safety and unsafe working practices have been reported to them.
Denise Walker, regional organiser for the GMB union, which represents around 300 members in the industry in Ireland, said those who have spoken out against conditions have been "blackballed" on current productions.
She said workers are being asked to work an average 55 hour week, above the Organisation of Working Time Act limit of 48 hours average over 16 weeks.
Drivers have also been asked to work in excess of 12 hour days, she said.
Ms Walker said she accepted that some productions required flexibility but the work could be split between more workers and create more employment.
John Arkins, General Secretary of the Irish Film Workers Association said freelance contractors in the sector are not covered by employment legislation.
He accused SIPTU of allowing producer companies to abdicate their responsibilities under employment legislation and their use of collective agreements.
He said that some of these agreements include up to 66 hour weeks before overtime and there is no reason why productions cannot abide by the rules.
Mr Arkins also said that nothing has been done to address the lack of training in the sector.
He claimed that Screen Training Ireland does not engage with trainees in the industry and fundamentally failed to implement recommendations of previous training reports.
Mr Arkins said Screen Training Ireland is a drain on the taxpayer and should be returned to the further training and education authority, Solas.
He said a current production in Ireland has 80% of crew employed from New Zealand and the UK while experienced workers and trainees here are sitting at home.
People Before Profit TD Richard Boyd Barrett asked if the union representatives were claiming there were illegal employment agreements in place between some unions and Screen Producers Ireland.
He said, if this was the case, there would be a responsibility on the committee to respond.
Mr Arkins said there was a situation where people were saying to the Workplace Relations Committee that they were not employers, yet they had received €10m euro for a production.
He said it was untenable, unacceptable and needs to be changed.
Driver John Ward told the committee he has been working consistently in the industry for 11 years which he said shows there is the potential for consistency in employment.
He said he had been "blackballed" after working for 20 years in the industry once he asked about his hours.
Mr Ward said he had worked on some productions for 70/80 hours and he had effectively stood in a field for 15 hours and was not paid for it.