A "precious" pair of historic cups has been stolen from a National Trust property in Isleworth.
The Berlin porcelain cups, along with their lids and saucers, were taken from the house at Osterley Park on Thursday (July 16), during opening hours.
A cabinet at the estate, in Jersey Road, is understood to have been forced open and the items removed some time between 11am and 4pm that day.
The cups were inscribed with busts of Russian ruler Catherine the Great and Prussian king Frederick William II, both of whom reigned during the 18th century.
Made between 1770 and 1775, the cups are described as being dark blue and painted 'en grisaille', with heavy gilding in the Sevre style, flower spray finials and branch handles.
Osterley Park's house and collections manager Ellie Jones said: "The loss of these items from the collection is devastating to Osterley.
"Each piece is extremely precious to us and we urge everybody in the area and in the industry to keep an eye out for these pieces in the hope they may be safely returned to us."
Anyone with information about the stolen items is asked to call police on the non-emergency number 101 or the National Trust on 020 8232 5068.