The toilet, valued at more than $5 million, was part of an exhibition of work by Italian conceptual artist Maurizio Cattelan.
The toilet, named “America”, was previously on display in a cubicle at New York’s Guggenheim Museum, where more than 100,000 visitors were able to use it.
A 66-year-old man was arrested in connection with the theft, on the same day as the theft.
Police have arrested a second man, 36 years old “from Cheltenham on suspicion of conspiracy to burgle.” Suspect number two has been released under investigation.
The valuable artwork, however, is still missing