Police said Thursday they had detained a 67-year-old man who was among six people found at the farm in the rural eastern Netherlands.
Earlier, an investigating judge ordered another suspect, a 58-year-old man who rented the farm, detained for a further 14 days on suspicion of involvement in "deprivation of liberty and harming the health of others." The second suspect was held over the same allegations.
Police say the six people found at the farm, together with another man who managed to leave and raise the alarm, say they are from the same family. Detectives are investigating their precise relationship.
Copyright 2019 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.