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Company investigations - an honest story

Transparency - according to many a basis for successful business. We are happy to concur with that. Say what you do, do what you say. Simple, right? Yet this doesn't seem simple for everyone, even within corporate investigations.

Private investigation, also known as corporate investigation, is a niche, a profession for specialists. Indeed, becoming a private investigator (some refer to it as 'detective', others as 'private investigator') does not happen overnight. In the years when our staff still worked for the police, 'the criminal investigation department' was a department that many colleagues looked at with longing and admiration. The CID, then you had made it. Even now, in the private sector, you don't become a detective overnight, and that's a good thing. Just as you cannot learn the trade of carpenter from an LOI booklet.

Clients entrust their misery to a private investigation firm. Financial damage, buckets of stomach ache, sleepless nights. So it is nice for the client to know that 'his file' is in good hands. Is that not so?

Clients (and potential clients) deserve an honest story, if only because they do not put their trust in the hands of a detective agency for nothing. After all, trust that has already been (severely) damaged once...

For corporate investigations in the Netherlands, but also abroad, Interro is the place to be. Because corporate investigation has to be an honest story, and because investigation is a profession in which many aspects play a major role. Investigating is not a hobby, not something you just learn or do on the side. Knowledge, experience, analytical ability, communication skills: I possess these qualities and use them every day for the best possible result. That is why clients choose Interro.

About Interro (and John Warrink)

Interro for 10 years consisted of one department, one person. That person, that person is me: John Warrink. Founder with a desk, an iMac, a phone and a network. In recent years I have built a network of good, reliable specialists that I gratefully make use of when needed. People who have certain skills that I do not have, or who can work 'for me' or together with me on an assignment. People who all have permission to conduct private investigations. That could be a corporate investigator, but also observers, forensic IT specialists, IT security specialists or forensic accountants are in my extensive and strong network.

15 years of police experience and more than 20 years of private investigations ensure that I know how things work. The extensive experience I have gained in all these investigations, combined with my enthusiasm and analytical abilities are the building blocks for a thorough investigation every day, but also for a wonderful portfolio of clients.

Now Interro Recherchediensten B.V. is part of Security Network, a multidisciplinary company within the security domain. Together with the enthusiastic new board members and employees we can serve our customers even better, faster, more efficient and more complete. Interro is now also the point of contact in the field of TSCM ('sweeping' of vehicles and spaces to check for the possible presence of listening devices, GPS tracking devices and/or hidden cameras). More and more reports appear in the news about Dutch celebrities who have been robbed of their Rolex or other expensive possessions. A good preventive approach is essential, and Interro (in the person of Joram Okkerse) is your point of contact for this.

Flexibility, quality and enthusiasm

The clients of Interro know: when I call Interro they take all the time they need for me, without immediately pressing the stopwatch, whether it's in the morning or at 9 p.m. I'm sure they do. 'Walking the extra mile' is what they call it in English. Our clients know that we keep appointments and that their 'problems' are in good and trusted hands with Interro Recherchediensten as a corporate investigation agency. We like to think along, and by going the extra mile we like to prove our added value.

Core values

Transparent and honest

Transparency - according to many a basis for successful business. I gladly concur with that. Say what you do, do what you say. Simple, right? Yet this doesn't seem simple to everyone, even within corporate investigations. At Interro , you can trust that you will be told an honest story. Many detective agency websites talk about "our employees," and "we. It might be useful to know that many(most) detective agencies in the Netherlands consist of one person. There is nothing wrong with that (after all, Interro also consisted of one person for 10 years), but if you are looking for a reliable agency, don't be (mis)led by texts on websites.


We sometimes jokingly say that a workday lasts 24 hours. Clients know they can call us at any time (preferably not after midnight, but what has to be done, has to be done). If no one from our team can be reached for a moment, we will call back quickly.
Do we need to jump in the car at 10 p.m. to work on a case? No problem. Do workdays last longer than 12 hours? Then we rake it in. Even on weekends we are often at work.
That is the disadvantage of an incident-related profession. After all, fraud and crime are never committed by appointment.


In recent years our investigators have built up a large network that we gratefully make use of when necessary. People who have certain skills that we do not have in-house, or who can work 'for us' or together with us on an assignment. People who all have permission to conduct private research. Observers, IT specialists, tactical investigators: we know where to find the right people. Also abroad.

If you have a question that we ourselves may not be able to answer, ask it anyway. We will gladly put you in touch with the right people.

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