A range of historic items valued at more than £1,000,000 were stolen from the castle on May 21, including Rosary Beads belonging Mary Queen of Scots.
Detectives investigating the burglary have now issued photographs of a man they want to identify.
The man is described as white, in his 30’s or 40’s, with dark coloured hair and a high hairline, wearing a dark coloured tracksuit top and bottoms.
He is not believed to have connections in Sussex. The investigation has so far shown links to Kent, Oxfordshire, Gloucestershire and West Mercia and these images were taken in June this year at the Clacket Lane service area on the M25.
Detective inspector Alan Pack of Sussex Police said; "Our investigation into the Arundel Castle burglary remains live and we are keen to identify and trace this man.
"If you can help identify him or if you have any other information about this burglary, please contact us either online or by calling Sussex 101, quoting Operation Deuce.
"We also remind people that the insurers have offered a substantial reward should any of the property be recovered intact."
The list of stolen items includes:
1. Mary Queen of Scots Rosary Beads;
2. Seven gold / silver-gilt coronation cups (George II, George III, George IV, William IV, George V, George VI and Elizabeth II);
3. Gold Earl Marshal’s baton;
4. Gold and enamel baton;
5. Other miscellaneous items including ten silver-gilt Apostle Spoons, a silver-gilt casket with hunting and fishing scenes, and a silver-gilt mug.
In June a reward was offered on the basis that any items stolen are returned in their original, undamaged, condition, subject to specific conditions, and anyone with information can contact Simon Jones at loss adjusters Quadra Claims Services Ltd, email [email protected], phone 0161 838 6600.
A man aged 45, was arrested on suspicion of the burglary at an address in Eckington, Worcestershire, on 21 September by Sussex Police officers in a joint operation with Gloucestershire Constabulary, West Mercia Police and Thames Valley Police. He is currently released under investigation.