Home repairs left Banksy Spy Booth mural as rubble
A Banksy mural was accidentally reduced to rubble by workmen carrying out repairs on a Cheltenham house, its homeowner has said.
Spy Booth, showing three figures "snooping" on a phone box, appeared three miles away from government listening post GCHQ in 2014.
David Possee said when work began on urgent repairs to a wall, the artwork "came away with the bad render".
The council said it would be investigating.
Since it appeared on the side of Mr Possee's end-of-terrace property in Fairview Road, the mural has been fought over, defaced and vandalised several times.
In a bid to protect the artwork under the property's Grade II listed status, it was granted retrospective planning consent in 2015.
The council served notice on Mr Possee to fix what looked like damage done in an attempt to remove the artwork and to repair the rendering by April 2016.
"I just want people to know that I wasn't trying to sell it and it wasn't taken off deliberately," Mr Possee told the BBC.
"Where the Banksy is, it's got to be of sound condition and unfortunately when they were taking it off to try and find solid backing, the Banksy came away."
Mr Possee, who was once offered more than £1m for the mural, said he was working closely with the council.
"I've actually taken all the pieces that I could recognizably save and I've handed them in and Cheltenham Borough Council have them," he said.
"I didn't ask for this, this is my livelihood and I've not been able to rent the house out now for two-and-a-half years."
Mark Nelson, the council's enforcement manager, said: "We have endeavoured to protect the Banksy as much as possible and to this end the notice required the owner to have due regard for the mural whilst works were being undertaken.
"We were aware of loose render on that part of the building but the extent and how far it would affect the mural was unknown until work progressed.
"We would advise anyone against removing any further pieces from the location as this may be classed as a criminal offence."
Philip Staddon, from Gloucester-based PJS Development Solutions, said it was "difficult to ascertain" exactly what had happened but when the Banksy appeared in 2014 there had been "no obvious signs that the render was failing".
"Recent pictures of the wall and rubble pile indicate to me that a concerted building operation has been involved to remove the render - either manually or with a power tool - as it is stripped back to the underlying brickwork."