A pair of mid-15th century medieval panels have been stolen from a church, police said.
The panels are believed to have been hacked out of a section of The Holy Trinity Church in Torbryan, Newton Abbot, Devon at some point between August 2 and 9.
Thieves hacked the two panels, depicting St Victor of Marseilles and St Margaret, from their casings, as well as smashing a gaping hole in a third.
Police described the artistry as being of a very high standard and the Churches Conservation Trust said the screen was one of the most important examples of its kind in the country.
They fear the panels could be resold or even exported internationally.
Devon and Cornwall Police have launched a national appeal for information, believing the panels could be somewhere else in the country.
The Torbryan screen was described as being of "national interest", as one of the only examples to have survived the "worst excesses of the iconoclasts" in the late medieval period.
Crispin Truman, chief executive of the Churches Conservation Trust, said: "I was shocked to learn of the theft of these panels and the damage done to this significant art work.
"Holy Trinity is a beautiful building much admired around the country and beyond. This crime will deprive all visitors and researchers of an important part of Devon heritage and is essentially a theft of public property. We hope that by publicising the loss we might recover the panels and ask anyone who might have information to contact us."
Pc Gareth Beynon, who is investigating the theft, said: "We are keen to find out what has happened to these ancient panels. They are very distinctive and may be somewhere else in the country. We are appealing for anyone who knows where they are or who may be responsible to get in touch."