Italy's highest court ruled on Friday that lobsters must not be kept on ice in restaurant kitchens because it causes them unjustifiable suffering before they head for death by fine dining.

Judges accepted a complaint by an animal rights group against the owner of a restaurant near Florence who kept live crustaceans on ice, ordering him to pay a 2,000 euro fine ($5,593) and a further 3,000 euros in legal fees.

Upholding a sentence by a lower court, the Cassation court ruled that the fact that lobsters are usually cooked while still alive does not mean they can be mistreated beforehand.

"While the particular method of cooking can be considered legal by recognizing that it is commonly used, the suffering caused by detaining the animals while they wait to be cooked cannot be justified in that way," the judges wrote.

Rather than keeping lobsters and other crustaceans refrigerated, the court said it was already common practice in high-level restaurants and even supermarkets to keep them in oxygenated water tanks at room temperature.