De Jong was born in Amsterdam and grew up there. In the early 1990s, De Jong earned a lot of money trading large quantities of weed. As a driver he transported the weed and also smuggled it to the United Kingdom. The police and Public Prosecution Service saw these and other drug transports, but let it go in order to get to the top of the criminal organization with leaders like Mink K. and Stanley Hillis. This became known as the IRT Affair. It caused commotion in 1993 because police officers also turned out to be dealing in drugs and earning millions themselves. There came a parliamentary investigative into these controversial investigative methods, led by politician Maarten van Traa. He had a verdict in 1996 that also led to a stricter legislation.