Universities could face expensive legal action and embarrassing ethical questions if they don't formulate rules on how to manage their cultural property.
The warning comes from University College London, which has become the first UK university to adopt a policy on the materials and objects it acquires, from paintings to anatomical specimens.
Sally MacDonald, director of UCL museums and collections, said: "In a research-active university like UCL, people are working with cultural property all the time, in a range of different disciplines. Academics and researchers have to be aware of the implications of working with it and recording what they do."
Recently, UCL was offered a collection of pottery from Egypt, but had to decline because there was no export documentation in place, she said.
It also owns a Native American headdress, acquired 15 years ago to aid a conservation student in their studies. Yet the university does not know whether it was bought, donated or loaned, or where it was acquired. The new policy will tackle such problems, she added.
Ms MacDonald explained that museums and curators follow similar policies as a matter of course.
"Academic freedom is tremendously important, but we're not outside the law," she said. "If you're found to have material that has been acquired without proper procedures and has been illegally imported, that's a problem."