A South Korean court has taken the rare step of jailing a woman for secretly photographing a male nude model, in a case that has sparked accusations of sexism and double standards.

The 25-year-old woman, identified only by her surname Ahn, was sentenced to 10 months in prison by the Seoul western district court and ordered to undergo 40 hours of counselling on sexual violence.

South Korea is in the midst of an epidemic of spycam pornography, where victims are secretly filmed in places such as toilet stalls and changing rooms. A series of monthly protests in Seoul have drawn tens of thousands of people.

The number of spycam crimes reported to police surged from around 1,100 in 2010 to more than 6,500 last year. It is thought many crimes go unreported.

Of the 16,201 people arrested between 2012 and 2017 for making illegal recordings, 98% were men, including school teachers, college professors, church pastors and police officers. Of the 26,000 recorded victims over that period, 84% were women.

Ahn, also a nude model at an art school in Seoul, was arrested in May days after she posted a photo of her male colleague after an argument over sharing a rest area. Her arrest was highly publicised and covered by a phalanx of television cameras.

Activists have pointed to the uncharacteristically swift police response and harsh punishment as evidence of ingrained sexism in the justice system. Many male perpetrators have been required only to pay a modest fine. The vast majority of first-time offenders receive suspended sentences or fines, with only about 9% handed jail terms, according to government data.

Police announced last week they were seeking to arrest the operator of a feminist website for hosting spycam porn, including the photo Ahn took. The news was seen as the latest injustice in a country where men dominate the halls of power. More than 70,000 people signed an online petition accusing the police of sexism.

Police have denied accusations that they fail to take women’s complaints seriously, citing the difficulty of verifying allegations based on footage that often does not show the victim’s face.