A sixth person has been arrested by police who are looking for a stolen solid gold toilet.
Police have yet to recover the $6m (£4.8m) artwork that was stolen from Blenheim Palace in the early hours of 14 September.
A 35-year-old man from London was arrested on suspicion of handling stolen goods and is in police custody.
The working 18-carat gold toilet - America - was in an exhibition by conceptual artist Maurizio Cattelan.
Visitors had been invited to use it as part of the exhibition.
The palace said its theft caused "significant damage and flooding" because it was plumbed into the building.
The stately home is a World Heritage Site and is the birthplace of Sir Winston Churchill.
Five other people previously arrested in connection to the theft have already been released while inquiries continue.
A 66-year-old man from Evesham was arrested on suspicion of burglary and a 35-year-old man from Cheltenham was arrested on suspicion of conspiracy to burgle.
A 34-year-old man, a 35-year-old man and a 36-year-old woman, all from Oxford, were arrested on suspicion of conspiring to commit a burglary of a building other than a dwelling.