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 issues, 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.


Private investigators in Australia must be licensed by the licensing authority relevant to the state where they are located. This applies to all states except the Australian Capital Territory. Companies offering investigation services must also hold a business license and all their operatives must hold individual licenses. Generally, the licenses are administered and regulated by the state police; however, in some states, this can also be managed by other government agencies.

Anyone can hire a private investigator. Frequent clients include:

  • Lawyers – Litigation support, skip tracing, process serving, intelligence gathering / divorce support services as well as locating hidden assets
  • Accountants – Asset searches, forensic accounting, shutdown support (security and investigations relating to liquidation)
  • Government Agencies – Department of Human Services - Child Welfare, Work cover and Centrelink fraud investigations
  • Corporations – Counterintelligence services, market research, undercover agents’ placed inside businesses to investigate fraud and theft
  • Private Individuals – From divorce support to child custody, matrimonial and neighbourhood disputes, counter surveillance and risk assessment

No, we do not have any arrest powers other than that of a fellow member of the public i.e. a Citizen’s arrest.

A private investigator can legally take photos and videos of you and your house unless they are trespassing on your land in order to do so or recording you undertaking private activities. Private investigators cannot bug your phone or use a listening device to record private conversations they are not a part of.

Often, people think if they perform an IP address lookup, that they are going to find the physical mailing address of the user assigned the IP in question. This is simply not true. At this time, we are not aware of any IP address database that will give you the exact physical postal address of the IP address you look up. At best, you'll get the exact city in which the user of the IP is located. For an exact physical address you would need to contact the ISP (Internet Service Provider) of the IP address in question.

However, without a police warrant, or some sort of legal document forcing the ISP to turn over the information they are unlikely to give it to you - Don't expect ISPs to give you the mailing address of the user that received the assignment of the IP at the time you received the offensive email. Moreover, even other means of offensive / questionable communication from said IP.

More often than not, private investigators do not have the legal authority to access information such as bank or investment accounts. ... However, a seasoned private investigator may be able to identify accounts linked to an individual through interviews, public records searches, or other legitimate investigative techniques.

Costs associated with hiring a Private Investigator vary depending on the type of service the client requires. Base rates for standard surveillance starts at $85.00 per hour plus reasonable travel and kilometer fees. Costs are negotiable when a job may require a week or more of surveillance or travel interstate or overseas.

Private Investigators regularly conduct background checks on individuals for a variety of reasons. Corporate clients utilise our background check services for pre-employment screening and fact checking resumes. Background checks are also useful for litigation and company directorship, land title ownership, character checks and finance and bankruptcy searches. Corporations often use our services to audit their workforce and senior management if tendering for multimillion-dollar contracts. We have also been engaged to check the criminal, civil, bankruptcy and social media records of board members prior to a company being listed on the ASX. If background checks are not undertaken in situations such as these, serious legal issues can arise from both shareholder and public. For example, if a board member is found to have a colourful or criminal past, this would have far reaching consequences.

Private sector clients also utilize our background check services for a range of matters including pre-leasing background / reference checks, dating profile fact checking (i.e. is the person I met online real or is this a scam? is a common inquiry).

We have been engaged many times over the years to assist in locating missing persons or to reconnect children to their biological parents. If a person has gone missing in the last 24-48 hours we strongly suggest you contact your local police department and submit a missing persons report.

Group One Investigations have assisted hundreds of clients seek out the truth when it comes to gathering evidence in cheating partner investigations.

We have assisted not only clients in Australia but also internationally track down parents who have attempted to hide from legal obligations. We have extensive experience in uncovering the true weekly income of parents who under report their financial position in an effort to avoid paying child support.

Child custody investigations are often required to prove or dis-prove that a parent is abiding by court orders. For example, if a court order is in place regarding children having overnight stays with one parent, but you are concerned that this parent is under the influence of drugs or alcohol, a private investigator can help uncover evidence to present in court. We can also help investigate claims in the opposite direction, such as if you are being accused of something you did not do, such as taking drugs or drinking when your children are in your case, to maliciously affect court orders.

Clients engage us prior to or during divorce cases in an effort to uncover hidden assets, a second family, trace funds being sent overseas to unknown individuals, diversion of funds, secret bank accounts.


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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

Need to Make Sure Someone is Who They Say They Are? Request One of Our Expert and Confidential Background Checks

In an ideal world, you would be able to take people at face value, but as we live in an increasingly imperfect world often we need to check that someone is who they claim to be, and that they are representing themselves truthfully. In that...
Read More about Need to Make Sure Someone is Who They Say They Are? Request One of Our Expert and Confidential Background Checks

Using Corporate Private Investigations to Protect Against Deception, Theft, Cybercrime, Security Breaches and More

Corporate Private Investigations With the world currently in the grip of a sweeping pandemic it has never been more crucial to protect yourself and your company from theft, deception, untrustworthy employees, and dishonest competitor practices. And, as the economy braces for a downturn, now is...
Read More about Using Corporate Private Investigations to Protect Against Deception, Theft, Cybercrime, Security Breaches and More

Using Private Investigators to Resolve Neighbour Disputes

Neighbours! Everybody needs good neighbours! But what if instead of finding the perfect friends, yours are complete rot bags whose idea of neighbourly behaviour is letting their dog bark at all hours, refusing to fix shared fences, dumping rubbish in community areas, playing deafening music...
Read More about Using Private Investigators to Resolve Neighbour Disputes

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