Tokyo police have arrested a 31-year-old man for allegedly creating fake sexual images of female celebrities with generative artificial intelligence technology and displaying them online, it was learned Thursday.

It is the first time that police in Japan have cracked down on sexual deepfake images of celebrities created with generative AI.

The suspect, Hiroya Yokoi of the city of Akita, has admitted he began making deepfakes to earn a small amount of money, which he used to cover living expenses and repay a student loan.

Authorities believe Yokoi made a total of about 20,000 sexually explicit images of 262 women, such as actors, television personalities and idols, and amassed sales of ¥1.2 million between October last year and September this year.

He was arrested on suspicion of displaying fake sexual images of three actors online over three instances from around Jan. 7 to June 2.

Yokoi explained he used free generative AI software and learned how to make the images from online articles and videos.

He made the fake images by feeding images of celebrities to a generative AI program.

He showed the generated images online to users who paid a monthly fee. Members who subscribed to a premium plan could request specific celebrities and poses for the fake images.

Sexual deepfake images have emerged as a societal problem, especially with cases in which young people are victims.

Last year, police nationwide identified more than 100 sexual deepfake cases in which young people were victimized, according to National Police Agency data. Of the cases, 17 involved generative AI, and the majority were cases in which fake images were created by classmates.

"There is almost no way to protect yourself" from such crimes, said Sumire Nagamori, head of private internet patrol group Hiiragi Net. "Anyone can be a victim regardless of gender or age."