Van Helsum was believed to have vanished .
The German Authorities believed Van Helsum spent the Summer moving from village to village with unconfirmed sightings at Van Helsum 's birthplace of Hengelo and Berlin .
Van Helsum was believed to have vanished , and the German Authorities believed he spent the Summer moving from village to village with unconfirmed sightings at his birthplace of Hengelo and Berlin .