New 'Banksy' work appears near GCHQ
14 April 2014 Last updated at 20:04 BST
"Guerrilla artist" Banksy is believed to be behind a piece of street art depicting three shadowy figures eavesdropping - three miles from the Government listening post GCHQ.
The artwork, which appeared in Cheltenham on Sunday, shows three men wearing sunglasses and using listening devices to "snoop" on a telephone box.
Banksy has not yet claimed the work but it bears his hallmarks, say experts.
CCTV from a local shop captured a van pulling up on the night the artwork appeared, as Steve Knibbs reports.