A police sergeant from the Pretoria West Training College is under investigation after he allegedly told a student to "prove" to him that she was menstruating.
The sergeant was arrested last Thursday and appeared in the Pretoria magistrate's court on charges of crimen injuria and indecent assault.
He cannot be identified as he has not pleaded to the sexual offence yet.
Police spokesperson Inspector Paul Ramaloko said the suspect was released on warning and the case postponed until this week.
Ramaloko said it was alleged that the sergeant was training female students last week when one wanted to go to the toilet, apparently for "hygiene reasons".
It is believed that the accused wanted her to prove that she needed to go for the reasons given and ordered her to lower her pants in front of the whole class. Only after the student complied did the sergeant allow her to go.