London (CNN) -- Clad in brown trench coats, dark glasses and trilby hats, what appear to be three secret agents huddle around a payphone box with listening equipment.
It's not a 1950s film scene but the latest street art attributed to Britain's famously anonymous graffiti artist Banksy.
The image -- apparently a comment on the issue of government surveillance -- appeared early Sunday, local media said, on a house wall in the provincial English spa town of Cheltenham, in Gloucestershire.
The location may be a reference to the town's role as host to Britain's Government Communications Headquarters, known as GCHQ -- the UK equivalent of the U.S. National Security Agency.
The NSA has been at the center of the spying row sparked by revelations by its former contractor Edward Snowden about the extent of government surveillance. Some leaked documents also make a reference to GCHQ, although the UK government says the listening agency operates only within a strict framework of controls.
Asked about the image, a spokeswoman for GCHQ said, "This is the first time we have ever been asked to comment on art. Although we are not qualified critics, we are as intrigued as the rest of the residents of Cheltenham about the appearance of the mysterious artwork.
"For those who are interested, our website gives a glimpse of what modern day intelligence operatives are really like, although some may be disappointed by the lack of trench coats and dark glasses."
Karen Smith, who reportedly lives in the house, told the Gloucestershire Echo newspaper, "It's pretty good. It livens the street up a bit. There have been a lot of people about today looking at it."
The artwork emerged a day before The Washington Post and United States arm of The Guardian were awarded a Pulitzer Prize for their reporting on the NSA revelations, described as "marked by authoritative and insightful reports that helped the public understand how the disclosures fit into the larger framework of national security."
Banksy's own website makes no reference to the artwork. It instead features what appears to be a new artwork showing a man and a woman apparently embracing but each looking over the other's shoulder at a smartphone -- perhaps a comment on our modern-day addiction to technological devices.
Banksy's last high-profile project was a month-long street art "residency" in New York City.
Each day of October, Banksy unveiled new works of art around New York. The works were then announced on his website and posted to Instagram. Many of the surprise exhibits followed his signature street-art style: stencils spray-painted on streets, walls of buildings and under bridges.