Do I need a bug sweep? Signs of eavesdropping and what to do first

Short answer: you may need a bug sweep if confidential information is reaching people who should not have it and the ordinary explanations have been ruled out, or if you are about to hold discussions valuable enough that someone would want to overhear them. A sweep checks rooms, vehicles and devices for hidden listening, recording and tracking equipment.

The strongest sign is a leak that fits a place. A competitor matches a bid figure that was only discussed in one meeting room. The other side in a dispute seems to know what was said in a private call. Details of a negotiation appear before anyone has been told. One coincidence proves little; a pattern tied to the same room, car or phone is worth acting on.

Some situations justify a sweep before anything goes wrong: board meetings ahead of a transaction, litigation strategy sessions, a move into new offices, work by outside contractors in sensitive areas, or the departure of someone on bad terms who had access to the building. Many businesses sweep routinely before such events rather than waiting for a suspicion.

Other signs are weaker than they look. A phone that runs hot, a crackle on a call or a battery that drains quickly usually has an ordinary cause. They are not reasons to ignore a concern, but they are rarely enough on their own.

What to do first: keep the circle small and do not discuss the suspicion in the room, car or on the phone you think is compromised. Do not start searching yourself or removing items you find; that warns whoever placed them and can destroy evidence of who did it. Make a note of what leaked, when and who knew, because that shapes where a sweep should focus.

A professional sweep combines a physical search with radio-frequency and electronic checks, and looks at phones, laptops and vehicles where the concern points to them. What happens on the day is set out in our note on what happens during a bug sweep.

Finding a device is the start, not the end. The question then is who placed it and how they got access, which may lead to an internal investigation, a report to the police or legal action. Intercepting someone's communications without lawful authority is an offence under the Investigatory Powers Act 2016, and a found device should be preserved and documented so that those options remain open.

The first conversation with Neel Chakrabarti is free and confidential. Call from a phone and a place you are not worried about; we will tell you whether a sweep makes sense and agree scope and fees before any work begins.

Cato & Veil practice note. General information, not legal advice.