Sister S Sebastina who was the principal of Sacred Heart school at the time when Ruchika was expelled, will face the inquiry by the Chandigarh police.
Earlier on Dec 30, a senior UT official said that since the principal of the school was on leave, she would be questioned regarding the case on Dec 31.
A magisterial inquiry was ordered by the UT Administration on the school's questionable role in the expulsion of the Ruchika Girhotra on Sep 1990, just a month after her molestation by former DGP SPS Rathore.
The school had earlier said that Ruchika was expelled due to non-payment of fees.
The inquiry was ordered following the a complaint lodged by Aradhana's mother, Madhu Prakash.