A Pakistani private school principal has been arrested from Karachi city over the alleged rape and blackmailing allegations, media reports said.

More than 45 women fell victim to the school principal, an Investigation Officer (IO) told Geo News.

The arrested principal was identified as Irfan Ghafoor Memon.

The head of the school used closed-circuit television (CCTV) footage to blackmail the victims while police also recovered 25 such short video clips from his cellphone, reports the Pakistani news channel.

The incident grabbed attention after one of the obscene videos of the principal and a teacher went viral over the internet.

The investigating authorities told Geo News that the office of the principal had been sealed and a forensics will be carried out.

The principal has been sent to jail on a seven-day physical remand.

A case has been registered with the Steel Town police station on the complaint of the state.

The first information report (FIR) includes provisions for sexual harassment, threatening, and blackmailing,  the IO said.

He added that the principal under the pretext of giving jobs would sexually abuse the teachers.

"The accused used to blackmail the women by filming videos," it added.