Russian police say that the Belgian met a violent death. They have started an investigation.
The body was recovered from a ditch among the Rossija Motorway near Jam-Izjora in Tosno District.
The Belgian is believed to have died as a result of injuries to the skull. His passport, a golden Rolex watch, his wedding ring and cash were still on the body.
The Belgian arrived in Russia from Frankfurt in Germany for a meeting with a Russian colleague, but disappeared in mysterious circumstances on 6 April.