Weta Digital has been told it needs to overhaul its workplace culture in a highly critical review.
More than 200 current and former staff were interviewed during an 11-week period, in an independent review conducted by Miriam Dean QC.
The review found that Weta Digital's HR practices, policies and processes were "immature" for an organisation its size and success.
The company's management systems, policies and processes were found to be inadequate in fully safeguarding crew from bullying, sexual harassment, sex discrimination and other inappropriate conduct.
Dean said the workplace culture was not "toxic", but there was a problem in pockets of the organisation.
She found the company lacked a single, company-wide culture and was instead, siloed, and pigeonholed, which meant crew were often unaware of what other departments were doing.
The company's culture needed significant improvement, some departments and realms more so than others, she said.
"Weta Digital's crew love their work and the people there, but they do not all love the culture. The company often asks too much of them, it does not consult them, it does not always treat them - or promote them - fairly and it does not always protect them against poor (sometimes even bad) behaviour by others," she said.
In total, Dean received 80 complaints from crew about incidents they regarded as bullying, as well as another 120 complaints of inappropriate conduct, either experienced or witnessed by interviewees.
Such behaviour took various forms, including aggression, such as yelling and throwing temper tantrums; passive aggressive behaviour, such as sarcasm and belittling comments and 'hazing', which involves testing new crew to put them in their place.
However, Dean said she did not hear complaints of such behaviour from the company's 1300 other crew.
"Some interviewees said they had never experienced or witnessed such behaviour, confirming the siloed nature of the company and the markedly different culture of its parts."
She also found that favouritism was rife and women were at a disadvantage, where three-quarters of the workforce were men.
This resulted in few women in top-level positions, especially in more artistic and technical ones, she said.
"Production is female-dominated, but even here, at the very top, men significantly outnumber women in VFX producer roles.
"Flexible hours or job-sharing were not always options available for new mothers."
In total, Dean made 17 recommendations, which include an overhaul of workplace culture, restructuring the HR and executive teams and the implementation of a women's leadership programme.
Weta Digital have been contacted for comment.