03 9110 3088
A private investigators office

About GSI Investigations

Leading the way

Experienced private investigators with a passion and drive like very few others in the industry
Founded in 2015, GSI Investigations is a Melbourne based private investigation agency with a wealth of knowledge and experience in what is an ever evolving and demanding industry. At GSI Investigations, we have an incredible network of experienced and results driven investigators who are passionate about what they do.
"At GSI we have an incredible network of experienced and results driven investigators who are passionate about what they do."
— Gavin Sinclair
Founder & Director
GSI Investigations has a proven a track record of obtaining desired outcomes through our extensive knowledge and investigative experience and by engaging in constant communication with you our client throughout operations right from the initial consultation.
All investigations are conducted both discreetly and professionally at all times and always in accordance with all state laws surrounding common practices and procedures in the private investigation industry. We offer investigative services in the Melbourne metro and regional Victoria areas.
Why Choose a Private Investigator?
Engaging a private investigator can be a crucial step in uncovering the truth. Our team of experienced professionals is well-versed in local laws and regulations, ensuring that all investigations are conducted ethically and legally.
Expertise and Experience
Our private investigators have years of experience in a variety of investigative fields. From infidelity investigations to corporate fraud cases, we have the knowledge and skills necessa.ry to handle your case effectively
Discreet and Confidential
We understand that privacy is of utmost importance. Our investigators conduct all operations with the highest level of confidentiality, ensuring your information remains secure.
Comprehensive Services
We offer a broad spectrum of investigative services, including: Infidelity investigations, thorough background checks to ensure peace of mind and for checking potential employees, tenants, or partners.Corporate investigations, family law matters, missing persons and bug sweeping.
State-of-the Art Technology
Utilizing the latest technology and investigative techniques allows us to gather evidence efficiently and effectively. From surveillance equipment to bug sweeping technology, we have the resources necessary to get results.
How We Work
When you contact us, we begin with a free consultation to understand your situation and objectives. Our investigators will outline a tailored action plan designed to meet your specific needs. Throughout the process, we maintain open communication and keep you informed of our findings.
Committment to Results
At GSI Investigations, we are dedicated to delivering accurate and actionable results. We take pride in our meticulous attention to detail and commitment to ethical practices. Our goal is to provide you with the information you need to make informed decisions.
Our Philosophy
At GSI Investigations we pride ourselves on our professional and ethical approach to all investigations. Exercising patience and persistence with a commitment to the truth and facts. With objectivity and professional detachment we maintain ethical responsibility and adapt to each cases unique diferences.
Why choose GSI Investigations
When you hire a private investigator, you need more than just someone with a license — you need trust, discretion, and results. Here’s why clients choose us:. Proven experience, discretion and confidentiality, tailored solutions, clear communication, trusted by business & individuals and cutting edge techniques.
Tailored Investigation Solutions
We don’t believe in standard templates. Every client has unique concerns, so we design tailored investigation solutions that address your specific requirements—whether it’s background checks, surveillance, corporate intelligence, or personal matters.

Over 160 years of private investigations experience

We have some of the industry's leading and most experienced professional private investigators in Melbourne who just happened to love what they do and are ready to help you to get to the truth!
Need our help?
Contact Us
  • Get in touch
Call us: +61 3 9110 3088 Email GSI Investigations
Location
Melbourne VIC 3000 Servicing Greater Melbourne and all of regional Victoria
Hours
Contact 24/7 via email or call us Mon to Frid: 7am - 9pm Sat and Sun: 8am - 8pm Surveillance: 24 hours 7 days a week
Tools
Copyright ©2015. GSI Investigations. All rights reserved. Private Investigator License 621 690 30S