Bugging graphic

Despite a crackdown on terror suspects, Britain stands almost alone in the West in barring phone tap evidence from being heard in court. Why?

Phone tapping is a common weapon in the armoury of detectives and government spies, so it may come as a surprise to learn that evidence from telephone taps cannot be used in court.

This long-standing principle was upheld this week by Home Secretary Charles Clarke following a government-ordered review.

Mr Clarke set out two reasons:

  • It would not make much difference because so much evidence depends on other forms of surveillance.
  • Technology is changing so fast, any regime put in place would soon be outdated.

The intelligence community is Mr Clarke’s biggest backer on this. It fears that allowing phone tap evidence to be heard in court could reveal its secret operational methods.

As it stands, tapes from conventional bugs – not attached to phones – can be used in court. Telephone conversations on an internal network can also be used and so can material where one of the people on the line is an undercover officer.

But a taped phone conversation between a suspect and a third party, on a landline or a mobile phone, is inadmissible. It can only be used for intelligence purposes.

At their most basic telephone intercepts link two people and give investigators information they then have to support by other means.

Gwyn Winfield, who publishes Resilience – a “global defence” magazine – says phone tapping is usually not enough to secure a conviction on its own because many conversations contain incomplete information, known as “intelligence chatter”, that requires context to make it meaningful.

“Telephone tapping is among the lowest forms of intelligence available,” he says. “It always has to be backed by something else – usually human intelligence in the form of a mole who could explain what the people are talking about and who they are.”

Conventional bugs are more effective because people tend to be cautious on the phone, he adds.


But Mr Clarke’s argument has not persuaded security analyst and former anti-terror intelligence officer Charles Shoebridge. Phone taps, he says, could have provided “compelling evidence” in recent terrorist cases, had they been admissable.

Similarly, advancing technology cannot be a good reason to delay legislation,” says Mr Shoebridge. “Otherwise new legislation would never be introduced at all. Technology is continually advancing.”

Other countries make regular use of telephone intercept evidence – indeed the UK and Ireland are alone in the West in not allowing bugged phone conversations in court. And before they can intercept calls, investigators have to get a warrant from the home secretary. The number of issued warrants is rising steadily – in 2003, almost 2,000 were issued in Britain.

Man on mobile

Covert calls can be heard but the tapes not used in court

Even then, phone tapping is not straightforward, says Michael Marks of Spymaster, which sells equipment to governments and corporations around the world.New mobile phones make bugging increasingly difficult. Conversations on old analogue phones could be heard using a £99 scanner, but today’s standard mobiles use encryption. A decrypting device to unscramble calls costs hundreds of thousands of pounds. The latest mobiles are even harder to tap, although landlines are still relatively easy.

“It’s a consistent leapfrog,” says Mr Marks. “As quickly as an encryption system comes out, lots of long-haired, pot-smoking geeks are trying to find a way to beat the encryption. It’s no secret that major governments have the equipment to listen to GSM [standard, digital] phones and they can ask the mobile system operators to help them.”

One aspect of phone tapping which the home secretary did not mention was civil liberties, perhaps because campaign groups have not been vocal about it.

Liberty – the civil liberties campaign group – does not object to intercept evidence being used in open court with a properly constituted jury. However, Privacy International has its doubts, fearing phone evidence would be presented to a jury as fact.