About Armsec
Built by operators, engineered for enterprise.
ArmSec is an Australian-owned provider of integrated security solutions, delivering end-to-end capability across physical, electronic and personnel security — trusted to operate where the stakes are highest.
OVERVIEW
Our vision is to become Australia’s most trusted capability-led security solutions provider.
ArmSec is a sovereign Australian security provider delivering integrated security solutions that combine skilled personnel, advanced technology, intelligence-led risk management and rapid response capabilities. Through a single point of accountability, we provide end-to-end security services from strategy and implementation to monitoring and incident response helping organisations protect people, assets and critical operations.
Supported by local expertise, industry-leading partnerships and continuous investment in innovation, ArmSec delivers scalable solutions that strengthen resilience and adapt to evolving customer and security requirements.
Executive Leadership
Experienced operators guiding every aspect of ArmSec's delivery.
Executive Team
Stuart Oliver
Chief Executive Officer
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Stuart Oliver is an experienced security and risk executive with over two decades of leadership across law enforcement and the private security sector.
Stuart commenced his career in law enforcement, serving from 2000 to 2012 in specialist high-risk policing roles. During this time, he developed deep expertise in operational command, risk mitigation, and managing complex, high-pressure environments.
In 2012, Stuart transitioned into the private sector, joining Linfox where he held senior leadership roles across security and operations until 2024. He was instrumental in strengthening security capability across a national logistics network, with a focus on compliance, governance, and scalable operational frameworks.
In 2024, Stuart was appointed Chief Executive Officer of Armaguard Security Services (ArmSec). As CEO, he is leading the transformation of ArmSec into a specialist, capability-led security provider focused on high-risk and high-value services, technology integration, and workforce capability uplift.
Stuart is recognised for his disciplined leadership style, commercial acumen, and strong focus on operational excellence, compliance, and people development.
Harry Stavrellis
Chief Finance Officer
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Harry Stavrellis is the Chief Financial Officer of ArmSec, bringing more than 35 years of financial leadership experience, including nearly 25 years within the Linfox Group in senior finance and executive leadership roles. He plays a pivotal role in shaping the company’s financial strategy, partnering closely with the business to drive sustainable growth, enhance performance, and support ArmSec’s continued expansion across the security sector.
Harry is responsible for finance, commercial management, governance, risk, and strategic planning across the organisation. Working closely with the executive leadership team, he helps identify and execute growth opportunities, evaluate new service offerings and acquisitions, and strengthen the systems, capabilities, and governance frameworks required to support a scalable and high-performing business.
Recognised for his collaborative leadership style and strong commercial acumen, Harry combines financial discipline with a practical, solutions-focused approach. He is committed to helping ArmSec deliver long-term value for customers, employees, and shareholders while supporting the company’s transformation into Australia’s most trusted capability-led security solutions provider.
Anthony Zagari
General Manager – Security Operations
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Anthony Zagari is the General Manager of Security Operations at Armaguard Security Services, bringing over 30 years of experience across law enforcement and the private security sector. A highly regarded operational leader, he specialises in managing complex security environments across guarding, aviation, critical infrastructure, and regulated industries.
Anthony has a strong track record in driving operational excellence, delivering risk management and compliance outcomes, and leading large-scale transformation initiatives that enhance commercial capability and stakeholder confidence. He holds qualifications in business, leadership, security risk management, and investigations.
Michael Kosaros
President –
Tech & Solutions
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Michael Kosaros is the General Manager of Technology & Solutions at ArmSec, where he is responsible for shaping and executing the company’s national technology strategy while driving the growth of its integrated security solutions portfolio. With extensive experience spanning system integration, security distribution, and technology leadership, Michael has built a distinguished career across the security industry.
Prior to joining Armsec, Michael held a senior leadership role with MotorolaSolutions, where he played a pivotal role in launching and expanding the company’s cloud business across the Australia and New Zealand market. His expertise in emerging technologies, solution design, and business transformation has positioned him as a respected industry leader.
At Armsec, Michael leads the continued evolution of the organisation’s technology capabilities, delivering innovative, scalable, and intelligence-led security solutions that help customers enhance security, improve operational resilience, and achieve their strategic objectives.
Careers
Join the team
ArmSec is building a workforce to match the ambition of its clients. Explore current opportunities across electronic security, guarding, transit and operations.