A police officer was arrested for allegedly raping a 13-year-old girl since March this year, Mpumalanga police said on Monday.

The officer was arrested in Moloto at the weekend, Superintendent Abie Khoabane said.

"When the first rape occurred, the girl reported the matter to her grandmother whom she lived with in Moloto. The grandmother did not believe her and the rapes continued."

The police officer and the girl were neighbours.

"After some months the girl's performance at school as well as the way she behaved changed... her teacher then took her for counselling, that is when she spoke of what happened to her. She was then taken for medical examinations."

Police were called in and the officer was arrested.