Three additional teachers from St Columbia’s School have been called for questioning as investigators analyse seized CCTV footage.
Police are cross-checking DVR footage with student statements and will question staff further after the preliminary technical review.
Delhi Police on Monday summoned three additional teachers from St Columbia's School for questioning in connection with the suicide of a Class 10 student who allegedly faced mental harassment, an official said.
Two of the three teachers previously issued summons were questioned on Sunday, and their statements were recorded.
The latest notices were issued after investigators seized a Digital Video Recorder (DVR) containing footage of an incident in which the student was allegedly reprimanded following a slip during a drama-club performance.
The father of the deceased student is expected to meet Joint Commissioner of Police (Transport) Milind Mahadeo Dumbere on Monday evening.
Police have begun a frame-by-frame analysis of the CCTV footage and are cross-verifying it with statements already collected from classmates and other students present at the time, the official added.
An FIR under charges related to abetment of suicide was filed after the student allegedly jumped in front of a train at Rajendra Place Metro Station on November 18.
In a recovered suicide note, the student named multiple teachers and accused them of sustained mental harassment. He also apologised to his family and expressed a wish to donate his organs.
Statements from several classmates and other students have already been recorded as part of the fast-tracked investigation.
Four staff members named in the suicide note — including the headmistress for classes 4–10 and the coordinator for classes 9–10 — were placed under temporary suspension shortly after the incident, a senior officer confirmed.
Investigators said they are examining CCTV and DVR footage, student testimonies, and school records to corroborate the timeline of events and determine whether the staff's behaviour constituted criminal harassment leading to the student's death.
Police said the staff will be called for further questioning once the preliminary technical review is completed.
