Kaur, whose house was raided by the CBI in Meerut in January, was summoned to the headquarters of the investigating agency and placed under arrest after being questioned at length over her alleged proximity with Moninder Singh Pandher, one of the main accused in the serial killings, official sources said.

CBI had claimed to have recovered from her house some files pertaining to the disappearence of some of the children and her questioning revolved around those aspects only, the sources said.

She was also questioned over her alleged attempt to scuttle the probe in the murder of a woman, Payal, who was allegedly sexually exploited by Moninder, they said.