Home Secretary John Reid has denied reports in today's Sun newspaper that the Home Office is planning to install millimetre-wave radar into lampposts that could scan under people's clothing.

The Sun claimed that a leaked Home Office memo from 17 January showed that civil servants considered using the technology, but were wary of public reaction. 

The memo allegedly stated: "Street furniture could routinely house detection systems that would indicate the likely presence of a gun, for example.

"The social acceptability of routine intrusive detection measures, and the operational response required in the event of an alarm, are likely to be limiting factors. Privacy is an issue because the machines see through clothing. "

One plan to allay fears was to use only female operators to scan women, but the memo suggests that this approach could be "problematic".

Such scanning technology is already available and a trial system seen by vnunet.com has been installed at Heathrow Airport.

The scanner uses a beam that only reflects off organic matter, allowing the operator to view the subject unclothed with inorganic material showing up as black marks.

The image was very detailed, showing not only the body of the journalist but a 2p piece that had been left in a back pocket. In the trials the journalist was only allowed to see the rear shot of the scan.

The Home Office told vnunet.com that it does not comment on leaked documents as a matter of policy, but Reid told BBC Breakfast that he had no knowledge of the plan.

"I have never considered this. We are considering greater use of technology in the case of terrorism or sex offenders, or more trivial offenders who would benefit from not being sent to prison, some of whom could be tagged," he said.

"Where appropriate we will use technology, but I do not know anything about this."