An 18-carat gold toilet is still missing and no-one has been charged with its theft two years after it was stolen.
The working toilet - entitled America - was taken from an art exhibition at Blenheim Palace, Oxfordshire, in the early hours of 14 September 2019.
At the time it was valued at $6m (£4.8m) and a reward of up to £100,000 was offered by insurers.
Seven people were arrested but never charged over the theft.
A gang broke into the 18th Century stately home and caused "significant damage and flooding" because the toilet was plumbed into the building.
It had been owned by a private individual and was part of an exhibition by Italian conceptual artist Maurizio Cattelan for two days before it was stolen.
Insurance firm Fine Art Specie Adjusters (FASA) said the reward, for safe return of the property leading to an arrest, still stood.
Director Philip Austin said: "No-one has come forward for the reward money yet... Initially there were lots of inquiries but now it's all gone quiet."
Thames Valley Police said all those arrested had been released while inquiries continued and no charges had been made.
Those arrested are:
- A 37-year-old man from London arrested on suspicion of handling stolen goods.
- A 68-year-old man from Evesham arrested on suspicion of burglary.
- A 36-year-old man from Cheltenham arrested on suspicion of conspiracy to burgle.
- A 38-year-old woman, a 37-year-old man and a 36-year-old man, all from Oxford, arrested on suspicion of conspiring to commit a burglary other than a dwelling.
- A 45-year-old man from Kent arrested on suspicion of burglary.
A Blenheim Palace spokeswoman said it was unable to comment due to the ongoing police investigation.
Matthew Barber, Police and Crime Commissioner for the Thames Valley, said "recovering the toilet would be a challenge".
He told the BBC: "Will we ever see that toilet again? Personally I wonder if it's in the shape of a toilet to be perfectly honest.
"If you have that large amount of gold I think it seems likely that someone has already managed to dispose of it one way or another.
"It would be great if we can recover it and return it but personally I'm not convinced it's still in quite the same form it was."
Art detective Charley Hill told the BBC in November 2019 he thought the toilet would have been cut up, melted down and the gold sold off.
Mr Hill previously helped solve the 1994 theft of an 1893 version of Edvard Munch's The Scream from an Oslo museum.