The controversial food is produced by force-feeding a duck or goose with a tube to specially fatten its liver by up to 10 times its normal size.
California’s legislature initially banned the state’s farmers from force-feeding birds in 2004, ruling that the process was unnecessarily cruel – the law was not implemented until 2011 – however, foie gras produced outside California was still sold in its restaurants and supermarkets.
Farmers groups in the state mounted a successful legal challenge from farmers’ groups, who argued that the ban was superseded by federal law.
The Poultry Products Inspection Act prevents individual states requiring products to have packaging, labelling or ingredient requirements which differ from federal standards.
But in this case, the appeals court judges' ultimately ruled that the ban on foie gras concerned a production process rather than an ingredient, and was compatible with federal law.
The ban will not be implemented immediately, in order to give restaurant owners and other retailers time to adjust to the new restrictions.