The Noida police on Monday evening questioned the family of Moninder Singh Pandher, the main accused in the serial killing of children in Nithari village of Noida, at his house in Sector 27 in Chandigarh.
Pandher's wife Devinder Kaur and son Karan were questioned, police told reporters after spending about an hour inside the businessman's palatial bungalow.
They added that a search of the house did not reveal anything connected to the serial killings.
Pandher mostly lived in the house he owned in Noida, where the skeletons of at least 17 children, suspected to have been killed by him and his servant Surendra, were recovered by the police last week.
Pandher has been in police custody since Friday.
His wife had strained relations with Pandher and both were separated, family sources said. She lives in Chandigarh with her son who was educated in Canada.
The Chandigarh police have stationed a 24-hour guard outside Pandher's house.
Bajrang Dal activists had on Sunday protested outside the house demanding death to the Noida serial killers.
A policeman whose child has been missing in Chandigarh for the last few months also created a scene outside Pandher's house on Monday afternoon.