How easy is it to carry out crimes on the streets from behind bars? Well first of all you need to know the right people and you need around £400.

This is why there has been a call to jam mobile phone signals from an inspector. This would stop crimes on the streets, including drug trafficking, and bullying within prisons.

It is believed that there are 3 times as many mobile phones in circulation than have actually been seized. So going on figures from 2008, 7000 mobile phones where seized, with a black market value of 9million.  This means that there are potentially 21,000 mobile phones in circulation in UK prisons.

The prison service say that blocking signals is a slow and costly process but the technology is out there. For each prison to have the technology would cost £250,000 per prison.

But…will signal jamming affect the public outside the prison? Is the technology there to be specific with the signal blocking? Or will they have each individual network track signals from inside the prison and maybe get an imei block? Would that be possible and more cost effective? Or would that be too much work for the networks?

Interestingly at this moment in time it is not against the law to be in possession of a mobile phone in prison, the only law is on smuggling the phone into jail.