Christian advocacy group FamilyVoice Australia is urging a review of media classification after parents noticed their children were distressed by watching films inappropriately labelled as 'PG'.

"The overwhelming majority of parents want changes to the classification system,” said FamilyVoice National Director Ashley Saunders.

“The categories G, PG, M and MA15+ are so broad that they give little information to families,” he said.

"Parents are telling us their children are frequently exposed to violence, especially in promotional clips in cinemas.

“Exposure to such gratuitous content leads to the normalization of physical violence, contributing to unrealistic expectations and sometimes outrageous copy-cat behaviour.” 

A 2017 survey by the Australian Council on Children and the Media found eight out of 10 parents thinks the classification system needs to change, and most wanted an age-based system.