In a law-enforcement first, a 57-year-old man was arrested Monday on suspicion of damaging the reputation of a female athlete by posting a video he secretly took of her in a sexualized context on a porn site, police said.

It is the first time Japanese police have applied the charge of defamation to the sharing online of sexualized photos and videos taken of athletes non-consensually -- a phenomenon that has become a growing social problem.

Personal computers and other devices are seized by police as they arrest a man in Chiba Prefecture on June 21, 2021, over the posting on a porn site of a sexualized video secretly taken of a female athlete. (Kyodo)

Hiroshi Ishigami from Ichikawa in Chiba Prefecture is accused of taking an eight-minute video of a volleyball player using an infrared camera to highlight her underwear under her clothes and charging people to view it on a porn site between November 2018 and March this year, according to the Chiba prefectural police.

The video was filmed while the athlete was warming up and when she was competing, they said.

Tens of other videos were posted on the site, including footage emphasizing the breasts and other parts of female athletes' bodies, police said.

Ishigami has admitted to the allegation, police said, adding they suspect he earned a total of around 6 million yen ($54,000) since 2015 through the sale of the videos, including at other websites.

Police conducted the investigation in cooperation with the Japanese Olympic Committee.

The issue of sexual videos of athletes first surfaced when female athletes complained to the Japan Association of Athletics Federations in August last year.

In November, the JOC and six other sporting bodies condemned nonconsensual capturing and sharing of sexualized images of athletes in a statement and set up a center to collect information.

In May this year, Tokyo police arrested a man for alleged copyright infringement after he posted images of several female athletes, accompanied by sexually explicit comments, without permission on a porn website he operates.

The Tokyo Summary Court later ordered him to pay a fine of 600,000 yen.

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