Banksy devotees in Cheltenham are mystified by the apparent removal of one of the graffiti artist’s murals from a local Grade II-listed house.

The only clue as to what might have happened to ‘Spy Booth’, which depicts three secret agents in trilbies and trenchcoats “snooping” on a man in a phone box with the aid of listening devices, came on Saturday (20 August). Pictures on social media appeared to show scaffolding and tarpaulins erected around the mural. The sound of machinery was also said to be heard and now all that remains is a pile of rubble beneath the wall of the house previously emblazoned with Banksy’s work.

‘Spy booth’ appeared in April 2014 on the corner of Fairview Road and Hewlett Road three miles from GCHQ, the home of the UK government’s surveillance operations. Just a few months earlier, computer analyst whistleblower Edward Snowden had made international headlines with the leak of classified National Security Agency documents on widespread phone-tapping by western governments.

The mural has been threatened several times with an attempt to remove it for sale in July 2014 and numerous instances of vandalism. Last year, an attempt to remove Banksy’s ‘Art Buff’ mural from Folkestone for sale in the United States was thwarted by legal action brought by the Creative Foundation on the advice of specialist Boodle Hatfield art lawyers.

In February 2015 ‘Spy Booth’ obtained listed status when Cheltenham Borough Council planners agreed to grant it retrospective planning permission. The retrospective consent to changes to the character of the building on which it appeared meant further permission would be needed to remove the mural from the wall. Now local residents and Banksy enthusiasts who fought to save the piece are at a loss as to its fate and whether or not it was destroyed during urgent building work carried out on the listed house or removed beforehand to enable the work to take place.

Leader of Cheltenham Borough Council, Steve Jordan, told the BBC that the council had issued an enforcement notice to undertake repair work on the plaster on the wall of the ‘Spy Booth’ house but he was unable to account for the Banksy’s disappearance. “It is protected by a listing. I will have a look at what the situation is, certainly,” Jordan said. The owner of the house, which was listed for sale with a guide price of £210,000 in January this year, could not be reached for comment.

Perhaps the key to solving the mystery lies in a cryptic tweet from a local resident: “It’ll be back. Plans have been made”.