Free Consultation: Contact Group One Investigations anytime, any day of the year.

Melbourne’s Leading
Private Investigator

Call us 24/7 on 1800 181 880 or email us to find out more about Group One Investigations, or read ahead for an overview of what we do and how we can assist you.

Call Group One Investigations on our 24/7 number

Private Detectives and Investigators

Group One Investigation

Group One Investigations is Melbourne’s premier investigative services agency, excelling in the field of private intelligence and surveillance for over twenty years. We provide discreet professionalism in all aspects of corporate and domestic surveillance. If you’re seeking information that has been obscured, you need an expert, and our private investigators have mastered their craft. Don’t let hesitation prevent you from accessing the expertise of a professional who can save you from the sense of regret from not having learned vital information or a valuable truth until it’s too late. Our agency is intimately acquainted with the methods and strategies that individuals will utilise in an attempt to pull the wool over your eyes. The best way to protect yourself from misinformation and to find out the truth is to hire investigators familiar with these deceptions and who have solved these cases before.

People will often attempt to obfuscate the truth, not always out of malice or spite, but sometimes simply because they feel the need to leave out details they believe will prevent them from finding success in life. Even still, it is important to exercise your due diligence in a world where small, delicate details can get lost amongst the abundance of information. Information is power, and while we wish we could all give everyone the benefit of the doubt, it is essential to separate the bad actors from the well-meaning. At Group One Investigations we pride ourselves on our professionalism and reliability. We offer cost-effective investigative solutions in a timely manner. Gaining a thorough overview of a potential client or employee’s background is essential in ensuring that your business interests are protected and can also give you peace-of-mind.

Group One Investigations are experts in surveillance, locating missing persons, intellectual property investigation and more. We offer surveillance, activity reports, undercover operations, investigating extra-marital infidelity, assisting in the safety of your teenagers, polygraph testing, email tracing and internet based investigations, uncovering fraud, employee theft and background checks, and other critical operations. Our agency focuses on results, meaning that our clients’ satisfaction is the foundation upon which we ensure we are the best private investigator agency in Melbourne. We are licensed by the Australian Government, so you can take comfort in knowing that every information gathering technique we employ is legal, and that our relationship with our clients is maintained under strict confidentiality. We are judgment-free and objective in our aims, and our private investigators will pursue every avenue and won’t give up until every option has been exhausted.

Our Services

  • Debugging of offices
  • Background checks of potential employees
  • Surveillance of workers
  • Computer hacking investigations
  • Employee theft
  • Breach of contract
  • Monitor of fleet vehicles (GPS tracking)
  • Fraud investigations
  • Comprehensive background checks on companies or individuals

Corporate Investigations and Surveillance:

  • Infidelity
  • Child custody
  • Teenage activity reports
  • Debugging devices
  • Polygraph testing
  • Online dating investigations
  • Background checks
  • Neighbour disputes
  • Sale and hire of surveillance equipment

Domestic Investigations and Surveillance:

What is the first step if I want to begin an investigation?

The first best step is to contact us on 1800 181 880 or

We will then require as much information as is possible from you on the organisation, individual or debtor you are having investigated. The more information we begin with the faster we can locate them and/or secure the intended information or evidence about any given situation. This will also be helpful in reducing costs to you.

Not all cases are identical and, as such, our investigation will be tailored according to your needs. Group One Investigations exercises the utmost care and confidentiality across all sectors of our work, and we aim to deliver cost-effective private investigation while utilising only legal means of obtaining the desired knowledge.

Our Company

Our Director has twenty years of experience in the industry, with all of their contractors having spent the same amount of time in the industry, if not more. We have an in-house lawyer, IT specialist with a Bachelor in Computer Science, a former AFP agent, and researcher. We also have a qualified polygraph examiner and debugging technician. The debugging equipment is state of the art. Additionally we have a specialist phone examiner and equipment to conduct this type of work, so you can rest easy knowing that we are at the very forefront of private investigative solutions. This applies both in terms of manpower and the investigative practices we employ and in utilising the most current technologies in the field.


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We are located in the city of Melbourne, however we have the resources, connections, and capabilities to take on cases nationally and internationally, with industry associates in every country around the globe. We can organise investigations and connect with our assets at short notice anywhere, at anytime.

Group One Investigation Blogs

Investigating to Impress | Private Detectives Melbourne

Establishing a good rapport with a prospective client within the corporate world can be exhausting. It gets worse when potentially millions of dollars are on the line and one mistake means they could move on to the next best option – one of your biggest...

Investigating infidelity – Cheating Partners

Investigating infidelity; playing the game! ”Some people treat relationships like video games – they play them, then when they get bored, they cheat.”This concept, in many ways, displays the reality of relationships in today’s day and age. A lot of your life is spent thinking,...

A day in the life of a PI

Going behind the scenes: a day in the life of a private investigator Run for cover! Dive behind the wall!  Grab your gun from the holster, tackle the criminal, get your handcuffs out! Oh, wait… that’s right, this isn’t a James Bond movie. What comes...

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