A man has been arrested in connection with the theft of historic treasures worth more than £1m from Arundel Castle in West Sussex.
Among the items taken on the night of 21 May were a set of gold rosary beads carried by Mary, Queen of Scots to her execution in 1587.
Sussex Police have said a 45-year-old man was arrested in Eckington, Worcestershire, on Tuesday morning in a joint operation with Gloucestershire Constabulary, West Mercia Police and Thames Valley Police.
The suspect remains in custody for interview.
Police said the items taken from the medieval castle are of "irreplaceable historical significance".
The collection, valued at more than £1m, comprised of:
• Mary, Queen of Scots Rosary Beads
• Seven gold/silver-gilt coronation cups (George II, George III, George IV, William IV, George V, George VI and Elizabeth II)
• Gold Earl Marshal's baton
• Gold and enamel baton
• Other miscellaneous items including 10 silver-gilt Apostle Spoons, a silver-gilt casket with hunting and fishing scenes, and a silver-gilt mug
In June, Sussex Police released photos of two metal ladders used by the thieves who broke into the castle and stole the items.
The ladders, one 6ft long and one 12ft, were found at the castle and had been used to gain access to the dining room area where a window was forced to gain entry.
Police said the ladders had "clearly been well used over some years" with each having some worn labelling. They added the longer one has some "distinctive black and yellow paint splashings".
Officers hope that someone in the decorating or building trade, or maybe someone who just had them at home, will realise they are missing and get in touch.
Detective Inspector Alan Pack of Sussex Police said: "Our investigation into the Arundel Castle burglary remains live and this action marks a significant step in our enquiries.
"I would encourage anyone with further information about this burglary to contact us, and also remind people that the insurers have offered a substantial reward should any of the property be recovered intact. You can also contact us either online or by calling 101, quoting Operation Deuce.
"We are very grateful for the co-operation of West Mercia, Gloucestershire and Thames Valley Police whose assistance demonstrates how together we will take action to seek to disrupt criminality of all kinds."
Insurers acting on behalf of Arundel Castle offered a "substantial reward" in June, subject to specific conditions, for the return of the stolen items in their original, undamaged, condition.
Anyone with information is asked to contact Simon Jones at loss adjusters Quadra Claims Services Ltd. They can email firstname.lastname@example.org, phone 0161 838 6600.