Medals awarded to Sir Edward Elgar have been stolen from his birthplace in Worcestershire.
The items taken, including a signed photo, were "irreplaceable" and "key elements" of its display at Lower Broadheath, the National Trust said.
They included Elgar's Grand Cross of The Royal Victorian Order, awarded for becoming a knight.
There was an "untidy search" after access was gained to the cottage at The Firs early on 27 June, police said.
An "unknown perpetrator(s)" got in at about 01:45 BST, the West Mercia force stated.
Local response PC Nick Garth said he would like to speak to anyone "who may have seen or heard anything in the early hours" in the area of the National Trust property.
He added: "The medals and the signed photograph are of high value to the National Trust and we are appealing for any information relating to their whereabouts."
National Trust general manager for the South Worcestershire Portfolio Michael Smith said it was "very upsetting".
He said: "The items that have been taken are key elements of our display and are of national significance. It is of paramount importance that we get these returned, they are irreplaceable."
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