Investigative Services

Our experience in crime investigation qualifies us to solve cases through examination, analysis and discovery. We will find and supply you with all the evidence and facts. Then you will be able to decide what to do next.


Defense Counsel

Workplace Testing

Drug Searches


ZeroStone are pleased to offer private businesses, companies & individuals Investigation Services in relation to fraud, staff theft, persistent reoccurring thefts (or shrinkage) and accidents or incidents at work. ZeroStone is licensed under the Private Security Personnel and Private Investigators Act 2010 (Licence number: 16-033106).

Mike can offer investigation, surveillance, monitoring and quality reporting of matters causing concern and loss to businesses and companies. He developed a Telephone Analysis System used extensively through the Tasman District and in the Canterbury and Southern Police Districts. The analysis formats raw data received from telco's in an easy-to-read format, and provides other post processing features. A similar analysis and formatting service is offered to lawyers with raw telco data. Mike's background in the NZ Police and criminal investigation will provide you with confidence and assurity that matters can be solved and dealt with - that may not be given priority by the Police. Mike has a Certificate of Approval to operate as a Private Investigator (Certificate Number: 16-033267).

Defense Counsel

Mike's 17 years of criminal investigation will assure Defence Counsel of insightful and relevant comment on criminal prosecutions. He is particularly skilled in telephone and text message analysis, and serious drug dealing investigation. He has worked on several major homicide investigations.

ZeroStone can offer investigation for Defence Counsel, including;

  • Interview of relevant witnesses
  • Preparing formal written statements for Court
  • Briefing witnesses for Court
  • Analysis of Prosecutorial disclosure
  • Comment on evidence in Prosecution case
  • Analysis of raw telephone call and text (SMS) data

  • Preparation of data into an easy-to-read format
  • Filtering of irrelevant conversations/contacts
  • Preparation of text data for Court Presentation
  • Comment and analysis of complex UFED or XRY cellphone extractions
  • Comment and opinion on serious drug matters and evidence

Law Enforcement Consultation

Whether you need investigation into businesses or private matters, or expert advice on matters of the law, we have the expertise to help you to take the right action.

Mike Lawson has a wealth of experience to act as a consultant in Law Enforcement matters. His experience includes serious crime investigation (including homicide), violence, sexual abuse (Adult and Child), dishonesty, fraud and drug offending. Mike has prepared many investigations for District and High Court hearings and has received commendations and acknowledgements for the work he has completed. Mike has specifically investigated methamphetamine dealing and supply over the last eight years. He has spoken with methamphetamine dealers and users, listen to live intercepts of their telephones, executed search warrants at their homes and spoken with informants and witnesses about methamphetamine manufacture, use and dealing. He has examined clandestine methamphetamine laboratories and processed methamphetamine exhibits and scenes with ESR and forensic staff. Mike has had “hands on” experience policing and examining the methamphetamine criminal underworld. He has also recently completed the inScience Methamphetamine Property Contamination testing Course and the NZQA Urine testing for Drugs Course, and is qualified under Unit Standards 25458 and 25511 to take workplace urine sample collection and in the procedures to send a medicolegal sample to the laboratory for drug confirmation and to conduct AS/NZS4308:2008 compliant on site urine drug screening.

Methamphetamine Testing

ZeroStone is located at the Top-of-the-South Island and provides reliable methamphetamine testing with a standard 2-3 working day turnaround for results, and a comprehensive report. We can test in Marlborough, Nelson & Tasman. Please see the test outlines below and feel free to contact us to discuss your options or for any methamphetamine queries or concerns.


The lowest cost screening option, which allows for samples collected from multiple locations at a property, but to be analysed in the laboratory as a single sample.


Up to 10 samples are taken from a property. They are taken as individual samples and placed in their own tubes, which are then are composited together in the laboratory.


Individual testing of rooms and areas in a property to identify levels of methamphetamine contamination.

Workplace Drug Testing

ZeroStone offer drug testing services for companies. We recommend and offer oral fluid testing, but can also conduct urine testing to screen for impairing substances in staff. We are proud to operate as the Nelson | Marlborough Drugwise NZ Testing Group.

Oral Test

There is much support of Oral Fluid as a drug test sample today as long as you use the correct and compliant product. ZeroStone can test employees for recent drug use, using Dräger DrugTest 5000 technology. The Dräger DrugTest 5000 tests saliva for recent drug use, which is likely to be affecting behaviour and performance undesirably. Testing Oral Fluids can have a range of benefits when it comes to drug testing. Some of those benefits are as follows:

  • Oral Fluid portable analyser systems make testing simpler/ less subjective than "do it yourself" testing
  • High cost of employee loss from urine drug test forrecreational use
  • Employee demand for a fairer test of potential impairment – acute impairment
  • Considered less invasive
  • Less potential for cheating
  • No requirement for bathroom facility

Workplace Drug Testing

Urine Test

Urine drug testing is a well established practice in today's workplaces as a part of their Drug and Alcohol Policy with many independent providers of testing services available throughout New Zealand. ZeroStone can also undertake urine screening tests and send medicolegal urine samples for scientific analysis at Christchurch Health Laboratories. ZeroStone technicians are NZQA Qualified: AS/NZS4308:2008 On-Site Urine Drug Screening. Below are some reasons it could be good to test urine.

  • Joint Australian New Zealand Standard
  • Lower cost per test than Oral Fluid
  • Two Confirmatory Testing Laboratories accessible in New Zealand
  • Preferred for Pre employment drug testing as it identifies Habitual and recent users

Credit Ann-Louise Anderson, inScience Ltd

Staff Searches

Our drug detection team of Dog Handler Matt MacDougall and German Shepherd Stone are fully accredited to locate drugs and drug equipment including: heroin, cocaine, MDMAs, methamphetamine and cannabis.

Different manufacturing processes and ingredients can affect drug odours, and our training methods and training aides ensure that these subtle variances are no barrier to their location and detection. Connect to ZeroStone Detector Dogs here.

Our Team

Our team, led by principal Mike Lawson, have a wealth of experience in serious crime investigation, including homicide, violence, sexual abuse (Adult and Child), dishonesty, fraud and drug offending. Mike Lawson, Matt MacDougall and drug dog Stone form our team. Combined we have over 50 years experience of crime solving.

ZeroStone Ltd is an owner-operated Blenheim-based business, servicing the top-of-the-south and beyond. Mike Lawson and Matt MacDougall have much more in common than their love of rugby and desire to serve the community - they are both ex-policemen who have been nationally recognised for their excellent contributions. Mike is a former NZ Police Detective who spent the majority of his 24 years in the Police working on a Drug Task Force. Matt MacDougall is our expert Dog Handler with over 10 years of NZ Police and Dog Handling experience - both as a General Purpose Dog Handler and with the Armed Offenders Squad. German Shepherd “Stone” is our star performer under the expert guidance of Matt.

Our Partners

We could not do what we need to do without the specialist partners that we work with. They include laboratories, scientists, computer technicians, rehabilitation and cleaners amongst others. They are an important, integral part of our family.

Contact us for more information or to organise a meeting or site visit.

We are located in Blenheim and service all of the South Island. However, we will work throughout the North Island under arrangement.