Click for homepage
Audiotel International Ltd

Audiotel International is a leading European manufacturer of TSCM equipment, used for the effective detection of electronic eavesdropping devices, also known as bugs. Audiotel TSCM equipment is generally sold world-wide under the Scanlock brand name. The company was established in 1978 and is commonly recognised as one of the major players in this field. On 3 September 2015, Audiotel International was acquired by Tioga Limited [11].

Audiotel equipment on this website
Audiotel Scanlock Mark 3
The Scanlock Mark VB analog bug detection receiver
The Scanlock 2000 semi-automatic bug detection receiver
The Scanlock ECM full-automatic digital bug detection receiver
First generation Non-Linear Junction Detector (NLJD)
Delta-V hand-held differential RF detector
Delta-V ECM
Small body worn transmitters and receivers for covert operations
Mains carrier transmitter (power line bug)
Subcarrier transmitter (FM/SC radio bug)
Cable checker for mains cables and (analogue) telephone lines
Audiotel wall probe microphone with extremely sensitive amplifier
Dummy bug, formed by a silicium ciode, in the shape of a hockey puck
Related equipment
COMPUSCAN add-on for the Scanlock Mark VB (developed by TSA)
Spectrum Monitor SM-2 (developed by TSA)
Lee Tracey
The history of Audiotel goes back as far as 1962, when Lee Tracey, a former RAF engineer and MI6 operative, invented the Scanlock receiver. Whilst working for MI6, Lee Tracey had developed a scanning receiver that was based on a novel technique known as a staircase or harmonic receiver.

 More about Lee Tracey

Technical Security Ltd
By mapping several smaller sections of the frequency spectrum on top of each other, the entire spectrum could be scanned for nearby radio transmitters (bugs) in less than a second. As MI6 had no interest in developing it further, Tracey started marketing it himself in 1975 through Technical Security Ltd. in London, at the time a front operation of MI6 [7]. In New Scientist of July 1975, it was announced that Technical Security would launch the Scanlock at a price of GBP 940 [8].

Audiotel International Ltd
A few years later, in 1978, Tracey left MI6 and founded his own company: Audiotel International Ltd., with its initial address at City Road in London. His first product was the Scanlock Mark I, soon followed by the Scanlock Mark 2 and the Scanlock Mark 3, Eventually this evolved into the now legendary Scanlock Mark VB. It instantly settled Audiotel's name as international experts in the field of countermeasures, and the Scanlock would soon be copied by other manufacturers [9]. For many years, the company used the silhouette of an eavesdropping man as the company logo.

In the US, Audiotel was represented by Technical Services Agency (TSA), founded by former CIA expert Glenn Whidden, With his technical expertise, Whidden enhanced the Scanlock Mark VB with an automatic scanning feature and signal memory, named COMPUSCAN. It basically converted the Scanlock Mark VB into a correlator, a technique the CIA has researched since the early 1960s.

Lansing Bagnall
As Lee Tracey was more of an engineer than a business manager, he teamed up with Lansing Bagnall in Basingstoke who took a major interest in the company by taking 70% of its shares. Tracey would concentrate on the development of the Scanlock and a new range of products, whilst Lansing Bagnall would look after product marketing and management of the company.

In the early 1980s, Audiotel started the development of the next generation of bug detectors, resulting in the improved (partly digital) Scanlock 2000. In Europe it was an instant succes and it soon replaced the Scanlock Mark VB. In the US however, the Scanlock Mark VB (enhanced with TSA's COMPUSCAN expansion unit) kept dominating the marked for several more years.

Andrew Martin
After a conflict between Tracey and Lansing Bagnall, Tracey gradually began loosing interest and fell out with the major shareholder. Finally, Lansing Bagnall decided to sell off Audiotel altogether and found a new owner in Andrew Martin, who led the company until his untimely death in 1997.

In 1987, Martin moved Audiotel to a new premises in Corby (Northamptonshire, UK). There, the successor to the Scanlock 2000 was developed, resulting in the digitally-controlled versatile Scanlock ECM. In the meantime, Audiotel had added a number of additional devices to their product range, such as the hand-held Delta-V and a range of covert communication devices.

Charles Bovill
In 1989, Audiotel got access to the latest developments in Non-Linear Junction Detectors (NLJD) by acquiring Security Research Ltd. from Cray Defence Group. Security Research was founded by Charles Bovill, a WWII SOE veteran and long-term friend of Lee Tracey, who had been developing and improving his Broom since the 1970s. Bovill developed the idea of the Broom during WWII, whilst working on other inventions like Eureka, Rebecca and the S-Phone [10]. At the time it was used to detect corrosion below an airplaine's painted surfaces. In the early 1980s the Broom appeared on the market and was actively being advertised in the security magazines of the days.

 More about Charles Bovill

The acquisition of Charles Bovill's NLJD technology, resulted in the release of the Broom ECM in 1990, soon followed by updates of existing products, such as the Scanlock ECM Plus in 1992, the Delta-V ECM in 1995, the SuperBroom in 1996 and finally the PC-driven Scanlock M2 in 2000.

PSG Solutions
After company director Andrew Martin's untimely death in 1997, Audiotel was acquired from the trustees of the estate on 31 January 2003 by London & Boston Investments plc (L&B) for a total amount of GBP 1,800,000. A year later (2004) Audiotel became a full subsidary of PSG Solutions, another L&B acquisition. In 2004, Audiotel reported a turnover of nearly GBP 3 million [4].

Today, the company is still based in Corby (Northamptonshire, UK) and supplies TSCM equipment to governments, law enforcement agencies, companies and private individuals world-wide. Early in 2013, Audiotel moved to a new premises, about 2 miles from the old one, and replaced the old familiar logo with the eavesdropping silhouette, by the red/blue one shown above [6].

Tioga Limited
On 3 September 2015, it was announced that Audiotel International had been acquired by Tioga Limited, with whom the company already had a good business relationship [11]. Tioga is one of the leading privately-owned contract electronics manufacturers (CEM) in the UK. After the merger of Tioga and Telemisis in 2017, Audiotel became part of the Simpatica Group, but kep trading under the old familiar name Audiotel International [12].

  1. On the first Audiotel website that was published in 1999, it was stated that the company was supplying products since 1977, the same year that was mentioned in the 1996 sales brochure [4]. A year later however, the website claimed Audiotel was established in 1978 [1]. We assume the latter to be correct.

Current address
  • Audiotel International Ltd.
    Corby Road, Weldon
    Corby, Northamptonshire NN17 3AR
    United Kingdom

    Phone: +44 (0)1536-464888
    Fax: +44 (0)1536-268363
  1. Full colour sales brochure 1996
    Audiotel International Ltd., March 1996. 16 pages.
  1. Initial Audiotel website:
    October 1990 - 8 September 2012. Retrieved via WayBack Machine. May 2013.

  2. Second Audiotel website:
    October 2007- August 2012. Retrieved via Wayback Machine. May 2013.

  3. Current Audiotel website:
    Retrieved May 2013 1.

  4. London & Boston Investments plc, Acquisition of PSG Solutions
    8 June 2004.

  5. Audiotel International Ltd., Full colour sales brochure
    March 1996. 16 pages, full colour. © Copyright Audiotel.

  6. Audiotel International Ltd., Audiotel International has moved
    Audiotel Newsletter, February 2013.

  7. Crypto Museum, Interview and correspondence with Lee Tracey
    23 May 2013.

  8. New Scientist, Boardroom electronic warfare
    Volume 67, Number 957. 10 July 1975, p. 66.

  9. New Scientist, Personal surveillance devices
    Volume 80, Number 1130. 23 November 1978, p. 601.

  10. The Telegraph, Charles Bovill Obituary
    9 May 2001. Retrieved May 2013.

  11. Audiotel, Audiotel International acquired by Tioga Limited
    Audiotel website. Retrieved November 2015.

  12. Audiotel, Website homepage, COMPANY
    Retrieved Octiber 2020.
  1. Although this website has been active since October 2000, it used to be redirected to audiotel-support [2]. Since the beginning of 2013, it is used as the main web address, whilst the others have been discontinued.

Further information
Any links shown in red are currently unavailable. If you like the information on this website, why not make a donation?
Crypto Museum. Created: Monday 13 December 2010. Last changed: Monday, 29 November 2021 - 10:47 CET.
Click for homepage