Torbryan screen panels stolen from Holy Trinity church
Thieves have "hacked out" two "nationally important" 15th Century panels from a screen in a Devon church.
The decorative oak panels, each containing a painting of a saint, were taken from Holy Trinity Church in Torbryan.
The Churches Conservation Trust (CCT) said it feared the panels could be sold abroad.
Devon and Cornwall Police said the thieves targeted the disused church between 2 and 9 August.
Maintenance contractors noticed the panels were missing while conducting a routine inspection.
The two stolen panels show images of St Victor of Marseilles and St Margaret. Another panel that has been damaged carries an image of a female saint.
They make up one of the few screens to survive the "puritanical zeal" of the Reformation and are one of the best examples of their kind left in Britain, the CCT said.
Crispin Truman, chief executive of the conservation charity, said there were originally 40 panels in the screen, each measuring about 45cm high and the width of a narrow floor board.
"Two of the panels have been viciously hacked out, leaving great big gaping holes," he said.
"These are fantastic examples of craftsmanship of the time. We think that this was probably the best preserved medieval rood screen in the country."
There are concerns the panels could be sold abroad, but Mr Truman said: "The value of these panels is in the building, they belong there. They are essentially priceless."
He said the panels were part of the fixed fabric of the church, so while the trust was aware of the risk providing greater security was difficult.
"There is only so much you can do and we want these churches open to the public so people can enjoy the original art in its original location.
"While moveable objects can be locked away, where do we draw the line because if we'd removed these amazing panels then we'd be the vandals.
"The trust is run by volunteers, so even if we had the funds to install CCTV, we wouldn't be able to monitor it round the clock."