The members of Dhaka Metropolitan Police’s Detective Branch arrested Hena, who was in-charge of Aritry’s section, at her Uttara home in Dhaka late in the night on Wednesday.
M Atiqul Islam, an assistant commissioner of DMP’s DB, told bdnews24.com about the development.
The two others accused in a case started by Aritry’s father Dilip Adhikary are Acting Principal Nazneen Ferdous and morning shift in-charge Zinat Akhtar.
In the evening, the institution’s authorities sacked the trio following government orders after two days of protests surrounding the death of a student.
Earlier in the day, the government cancelled the facilities the three teachers had been enjoying under its monthly pay order or MPO programme.
The education ministry also asked police and Rapid Action Battalion to act against them following the case started by Dilip.