Ms Fern, a student at the University of Southern Queensland, said the studio offered to promote her as a model without any need for a contract.

After negotiating what she would be comfortable to wear and how she would pose, she agreed to have her photos taken for a lingerie store in Sydney.

She was told the photos would be distributed in magazines, social media including Facebook and Instagram, in the store and on billboards around Sydney.

"At the fitting, I was asked if I would be comfortable wearing certain types of lingerie and I said no," she said.

"I told the client at the fitting: "I do not want to do anything that I would not show to my grandparents or little brothers and sisters."

Without a formal contract, Ms Fern was unclear how she would be paid.

"No one could give me a clear answer," she said.

"I paid for my own return flight from Brisbane to Sydney including all of my own expenses for accommodation and travel to and from the venue.

"I did not receive payment for the photo shoot from the client. The client did not tell me where the photos will go, how long they will be used for or when they will be used."

A University of NSW conference on industrial relations issues will on Thursday hear that fashion models are increasingly at risk of exploitation in the gig economy with little legal protection against being underpaid or unpaid or sexually harassed.

Many fashion and photographic models do not formally have an employer or a fixed place of work to qualify for protection under the Fair Work Act.

Michael Walker, a PhD student at the University of Technology Sydney and communications officer at the modelling union – the Shop, Distributive and Allied Employees' Association – will present a paper to the conference raising concerns about an increasing proportion of models engaged in informal employment.

"If this trend continues into the future it will mean the total collapse of modelling as a form of employment and a degeneration into informal employment," he said. "The protections of the Fair Work Act, with respect to pay, simply do not apply in an industry where almost no one works a 40-hour week and the small number who do are paid well above the award."

After flying back early from a family holiday in Canada for the photo shoot in August last year, Ms Fern asked for a contract and more details about where the photos would be used.

"I felt that I had done everything I could to make an informed, business savvy decision that aligned with my morals and would not impede on my career as an actress," she said.

"I was told during the shoot that some poses were needed for lighting and reference and that at the poses I wanted would be done after. Three hours were spent on these "reference" photos and 15 minutes on the shots that I had asked for."

After receiving a copy of some of the photos Ms Fern was "horrified at the results".

"None of the lighting or poses I had expressed in my wishes were delivered in the photos and instead the ones the client used were the "reference" shots," she said.

"I was extremely unhappy with the photos and they made me feel exploited, used and I doubted I would ever have a career in the modelling industry, given the unethical way this "job" was conducted."

Mr Walker said traditional modelling agencies are now often bypassed by models who accept jobs through social media, which provides little protection against exploitation. He said modelling, like acting and performing, is a form of "gig" employment.

"Having a lot of Instagram followers means that a person can become a recognised face without having to go through the traditional gatekeepers, the agencies," he said.

"People can put themselves directly out there on Facebook and Instagram and get work directly from that.

"It gives people more control over their personal brand, which is a good thing, but the down side of it is, it is just a payment for service."

Because modelling was such a competitive career without barriers to entry, many models were underpaid or not paid at all. Some were paid in the form of product samples.

If they are not paid at all, they are told that the exposure may help build their career.

"It may be that some people, including some of the models in question, don't really care and that modelling is not seen as a paid job as long as people have fun and learn from the experience," Mr Walker said.

"This is a defeatist argument that could be just as easily said of actors and musicians.

"It could be said of any job that a person enjoys."