The Government has moved to ban the sale of mobile phones which resemble car key fobs amid reports that prisoners smuggle the handsets into jail.
The tiny devices are said to be easily hidden from guards and enable inmates to make illegal calls or send texts while behind bars.
The Government is now clamping down on phones in prison and is in talks with the Serious Organised Crime Agency to ensure the miniature gadgets cannot be bought or sold in Britain. A report has suggested adverts for some of the Chinese-made phones were targeted at prisoners.
The handsets – dubbed the “world’s smallest mobiles” – are available on auction sites such as eBay and Amazon and are priced at around £40.
They are designed to look like the electronic fobs used to unlock vehicles and display the brand logos of various leading car makers.
The Prison Service said modern technology enabled guards to seize banned mobile phones.
A spokesman said: “A range of techniques – including Body Orifice Security Scanners and high sensitivity metal detectors – has seen the number of recorded seizures increase. “We’re now working closely with the Serious Organised Crime Agency and Trading Standards to remove these small mobiles from sale in the UK, as well as legislating to block phone signals in prisons.”