Police refuse to discuss whether they are behind the deployment of at least 20 'stingray' masts which trick handsets into logging on, giving access to all the owner's calls and other data
Rogue telephone masts which can listen to mobile phone conversations without the owner’s permission are being operated in Britain, it has been disclosed.
The technology, dubbed “stingrays”, trick handsets into thinking they are genuine mobile phone towers in order to monitor calls and other data including texts and emails.
Police have refused to discuss whether they are behind the installation of the masts, at least 20 of which were uncovered in an investigation by the Sky News
Privacy campaigners said the use of stingrays amounted to a “dragnet” of private phone calls which raised serious questions about checks and balances on the technology.
The controversial surveillance devices, known as IMSI catchers, are used in a number of foreign countries to target the communications of criminals.
But they also collect the data of all other handsets in the area, as well as other data from computers and tablets, leading to accusations of indiscriminate spying.
Eric King, deputy director of Privacy International, said: “Even when used by police, IMSI catchers are very difficult to use in a targeted manner, meaning when used in urban areas thousands of people’s mobile phones would be swept up in that dragnet.
“What police do with that data, we don’t know.
“With 20 IMSI catchers now confirmed to be deployed across London we need law enforcement to step up, have an honest conversation about their use, so we can ensure the public are being properly protected.”
Sir Bernard Hogan-Howe, the Met Police Commissioner, refused to discuss the technology.
"We're not going to talk about it, because the only people who benefit are the other side, and I see no reason in giving away that sort of thing,” he said.
"If people imagine that we've got the resources to do as much intrusion as they worry about, I would reassure them that it's impossible."
Sky News used special software by a German security company to find stingray activity in the capital.
The channel said it discovered more than 20 in London over three weeks.
Keith Bristow, director general of the National Crime Agency, said: "Frankly, some of what we need to do is intrusive, it is uncomfortable, and the important thing is we set that out openly and recognise there are difficult choices to be made.
"Some of what we would like to talk about to get the debate informed and logical, we can't, because it would defeat the purpose of having the tactics in the first place.”