The Defense Ministry has received at least 57 reports of sex crimes since it began operating a special reporting period from June 3. 

According to military sources on Wednesday, the ministry has requested formal investigations into 20 of the cases. As for 17 cases in which victims requested an inquiry, the ministry is likely to request formal investigations as well, depending on how the inquiries turn out. 

The military began operating the special reporting period following the suicide of an Air Force noncommissioned officer who had reported a sexual assault. 

Initially, the ministry was set to receive such reports until last Wednesday but decided to extend the period by two more weeks through June 30 after opinions emerged that the initial period was too short. 

Through active investigations and inquiries, military authorities plan to penalize those found responsible in line with laws and regulations. 

Last year alone, the number of sexual assault cases in the military reached 771, or about 64 cases per month on average.