About Us: SGI Head Office is based in South/West Wales and is comprised of a formidable team of multi skilled private detectives and investigators that have worked together since the business was founded by Sarah Gallienne in 2001 who, with a police background, decided to form an independent private investigation agency that would go the extra mile to deliver outstanding results for its clients, being approachable and taking the time to actively listen to what clients want to achieve.

With a combined experience of over 35 years, our team has grown complementing each other’s skills and building our agency on the high level of service we provide to our clients, both commercial and individual.

…More Info below

About Us

Offering a full range of Services including No Find / No Fee Tracing Services, and specialist Traces for the more difficult Traces, where minimal information is available or Surveillance Investigations to name but a few; we have an incredible success rate in bringing our client matters to a satisfactory conclusion, but you will not find any testimonials on the website. This is because, due to the nature of our work, our clients remain anonymous to ensure discretion and total confidentiality. As a client who has instructed us to follow your partner, husband or wife we are certain you would not want your name to appear here with a testimonial!

SGI personnel are all X Forces and highly trained in surveillance; RTA (road traffic accident) and all types of accident investigations; We also provide No Find/No Fee UK Tracing Services, Background Checks; Asset Reports; Test Purchases; Covertly filmed Gym Inductions; Enquiry Agent/Door Knock Enquiries; together with the supply of Store Detectives & Security Guards.

Our work is spread evenly between commercial and private enquiries. We work for solicitors, employers, local authorities, sports & leisure companies and indeed other private detective agencies when required to cover work in Wales on their behalf – as well as private clients – so no matter the problem, we are more than qualified to handle it.

We welcome enquiries from everyone!

With a team of local operatives working from our Head Office in Wales, having a good local knowledge of the geographical areas we work in on a day to day basis. Also having experienced agents operating throughout the UK we offer nationwide cover.


For many years our industry has been dominated by men but at SGI we also have female private detectives too. A lot of our clients feel more comfortable speaking to women about highly personal matters. Our reputation has been built on providing the right person for the job based on each individual client’s requirements.

In addition to our investigatory skills, we are also excellent listeners, aware that most of our clients come to us in times of distress and emotional anxiety. You will find our private detectives sensitive and understanding, honest and discreet so you can confidently discuss whatever is worrying you and be certain that if there is a way we can help, we will do so. As the saying goes – a problem shared is a problem halved!

Our private detective agency continues to evolve embracing the latest technology to provide our clients with the best professional service available.

Call us today to find out what we can do for you, or drop us an email via our Contact Us page if you prefer, for a same day response.