West Yorkshire police said today a three-day, multi-agency operation involved visiting 25 addresses across Leeds, in northern England, to help families identified as potential trafficking victims.
The force said 17 people mainly from Slovakia were rescued. Many were living in poor conditions with "little if any" income. It said others were being forced to work long hours for little or no pay.
Thirty-three other people approached during the operation "preferred not to cooperate and remained where they were," police added.