Update 14 April 2026: article reviewed; technical methodology, legal framework (art. 139f Sr, Wpbr) and pricing remain fully current.

TSCM (Technical Surveillance Countermeasures) is the professional detection and neutralisation of hidden surveillance equipment — such as hidden cameras, listening microphones and GPS trackers — in buildings, vehicles and electronic devices. A TSCM inspection is also known as a bug sweep or counter-surveillance inspection.

When do you need a TSCM inspection?

The need for a TSCM inspection arises in a wide range of situations:

You suspect your office, meeting room or home is being bugged
There is a suspicion of hidden cameras in a hotel room, Airbnb or holiday rental
A competitor appears to be aware of confidential business information
You are involved in a sensitive legal dispute or negotiations
You are a director, lawyer or executive conducting confidential discussions
After a break-in, renovation or staff change, you want peace of mind

Surveillance equipment is cheaper and more accessible than ever. A hidden microphone costs less than €20 and fits inside a power socket or USB charger. A Wi-Fi camera sits in a smoke detector or alarm clock. That makes the risk real — even for people and organisations who think they are not a target.

How does a TSCM inspection work?

A professional TSCM inspection combines multiple detection methods, because no single method is sufficient on its own:

Spectrum analysis (10 kHz – 24 GHz): Detects radio signals from active transmitters — cameras, microphones and GSM bugs broadcasting live signals. Professional equipment such as the OSCOR Green analyser scans the full frequency spectrum and identifies anomalous signals.

Non-Linear Junction Detection (NLJD): Detects electronic components based on material response, even when a device is completely switched off. An NLJD sends a low-power radio signal and measures the reflection from semiconductors. This makes even passive or switched-off trackers visible.

Optical camera lens detection: A specialised optical detection laser locates the reflection from camera lenses — including pinhole lenses of just 1mm diameter, hidden behind dark glass or fabric.

Physical inspection: Thorough manual inspection of power sockets, ventilation openings, smoke detectors, light fixtures, furniture and all objects that deviate from the standard furnishings.

Network and wireless analysis: Detection of unknown Wi-Fi devices, Bluetooth connections and GSM networks active within the area being inspected.

What does a TSCM inspection detect?

Hidden microphones and GSM transmitters
Pinhole cameras and Wi-Fi cameras (including when switched off)
GPS trackers under vehicles, in bags or packaging
OBD trackers (dashboard connection point)
Spyware on phones and computers (digital TSCM)
Unauthorised network equipment

Who is TSCM for?

TSCM is used by a diverse range of clients:

Companies and executives: Boardrooms, meeting rooms and offices where confidential conversations take place. Law firms and notaries who must guarantee client confidentiality. M&A negotiations and due diligence processes.

Private individuals: People who suspect they are being followed or surveilled. Stalking victims. Persons involved in divorce or alimony proceedings where confidentiality is essential.

Hospitality sector: Hoteliers who want to guarantee guest privacy. Business travellers conducting sensitive discussions in hotel rooms. Guests who suspect a hidden camera.

Is TSCM legal in the Netherlands?

Yes. TSCM — the detection of surveillance equipment — is completely legal. It is about protecting your own privacy or that of your clients. It is explicitly different from the placement of surveillance equipment without consent, which is a criminal offence under Article 139f of the Dutch Criminal Code.

SAJ Recherche holds POB licence 8779, issued by the Ministry of Justice and Security. We conduct TSCM inspections in accordance with the Private Security Organisations and Detective Agencies Act (WPBR) and GDPR.

What is the difference between TSCM and a bug sweep?

The terms are interchangeable. Bug sweep is the informal term for a TSCM inspection — derived from “bug” (English term for a listening device). In a professional context, TSCM is the correct designation.

What does a TSCM inspection cost?

Costs depend on the size of the location, number of rooms and desired depth of inspection. After a confidential intake conversation, you receive a fixed quote. See our pricing page for an indicative overview.

Frequently asked questions about TSCM

How long does a TSCM inspection take? Depending on the type of location: an office floor takes 2–3 hours. A full hotel suite or home 3–5 hours. A vehicle sweep takes 1.5–2.5 hours.

How quickly can a TSCM inspection be arranged? In urgent cases we are generally available within 24 hours, including weekends and evenings.

What if nothing is found? A negative result is also valuable: you have certainty. We provide a written inspection report regardless of the outcome.

What if equipment is found? We discuss the findings with you immediately. Depending on the situation, we advise on evidence preservation, reporting to the police (Art. 139f Sr) or legal follow-up steps.

How discreet is a TSCM inspection? We work in neutral clothing without conspicuous vehicles or equipment. Inspections can take place outside office hours. Staff or third parties notice nothing of the inspection.

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SAJ Recherche B.V. is a licensed detective agency with POB licence 8779, issued by the Ministry of Justice and Security. Registered in the WPBR register at Justis.nl. KvK: 96790954.

What is TSCM? Everything About Technical Surveillance Countermeasures