A nine-year-old girl was allegedly raped by a policeman at Madhupur in Terokhada upazila of the district on Monday.
Police detained Rezaul Islam, 22, from Mokampur village in the upazila in this connection. He served as a police constable at Natore Police Lines.
The victim is now undergoing treatment at the one stop crisis center of Khulna Medical College Hospital, said Anjan Kumar Chakraborty.
The condition of the victim is critical, he said.
Besides, victim's father filed a case with Terokhada police station in this connection, said Swapon Kumar Roy, officer-in-charge of the police station.
According to the case statement, Rezaul was visiting his village home on leave. On Monday morning, the girl had drifted near his house collecting flowers, when he lured the victim inside and violated her.
Later, the victim returned home and disclosed the matter to her mother.