Employers face the prospect of a crackdown over internships and work experience following a study to determine which unpaid work is lawful.

The Fair Work Ombudsman has commissioned two labour law experts to help clarify regulation of such arrangements.

Under existing workplace laws, employers can face fines of up to $33,000 per breach for failing to meet obligations in relation to unpaid work.

"There are instances where young workers have spent months - or even years - doing unpaid work that would ordinarily be undertaken by a regular employee," Professor Andrew Stewart of the University of Adelaide said. His colleague, Rosemary Owens, said in some cases workers might be entitled to be payment and other employment benefits.

Chamber of Commerce and Industry industrial relations policy manager Marcia Kuhne said she had not seen evidence of a need for greater regulation.

"One of the byproducts could well be that we see traditional unpaid work arrangements simply dry up," Ms Kuhne said.

Unions WA secretary Simone McGurk said small businesses such as fast food and beverage franchises had been known to use young people on work experience to do what should be paid work. "People need to be sure they're not being exploited," Ms McGurk said.