The NZ Herald reports that this comes after a survey by consumer group Choice showed that consumers who opt to take animal welfare into account in their purchases may be being duped.

"Just because a carton says free-range and has pictures of happy looking chickens adorning the cover doesn't mean the eggs have been produced to high welfare standards," said RSPCA Australia's Melina Tensen, adding that what is needed is a nationally consistent legal definition of the term free-range and other such terms that imply improved animal welfare standards, as well as much tighter regulation.

According to Tensen, consumers should look for eggs from producers that meet good animal welfare standards. "The RSPCA accredits barn-laid and free-range systems that ensure hens have access to nests, space to move freely, flap their wings and socialise, have constant access to food and water and are protected from predators and the elements," she said, adding that the RSPCA-accredited facilities underwent a stringent and regular inspection process to ensure strict welfare standards were being met.