An industry group is urging retailers to buy stamped eggs - after an Auckland man was sentenced to home detention for selling millions of caged eggs as free range. Frank Chen was sentenced to a year's home detention when he appeared in the Auckland District Court. Between late 2015 and October 2017, eggs were falsely labelled as "free range" and sold through a company called Gold Chick from a West Auckland Farm. In some cases, eggs were re-packed into free range cartons. The Egg Producers Federation executive director Michael Brooks told our reporter Chen Liu they're encouraging farmers and customers to stamp and trace eggs.