Lawmakers are introducing Japan's first laws against taking sexually exploitative photos or videos of others without consent.

The bill against "photo voyeurism" would prohibit acts such as upskirting and secret filming of sexual acts.

Until now, such criminal cases had to be prosecuted under local prefecture laws, which greatly vary in scope.

The bill is part of a wider overhaul of Japan's laws on sex crimes, which will also expand the definition of rape.

It explicitly prohibits the taking, distribution and or possession of photographs of someone's genitals without their consent.

It also criminalises the act of taking photographs of people being manipulated without their knowledge into sexual positions. Specifically, the bill bans the filming of children "in a sexual manner without justifiable reason".

In Japan, child models - mostly girls - are routinely portrayed in sexually provocative ways. For instance, some have been asked to pose in lingerie or swimsuits.

According to local media reports, photographs of athletes in sporting attire have sometimes also been used for sexual or malicious purposes.

Offenders would face imprisonment of up to three years or a fine of up to 3 million Japanese yen (£17,500; $22,000).

The reforms are expected to be passed in June this year.

It comes after growing public outcry for stronger laws criminalising acts facilitated by mobile phone photography.

In 2021, Japanese police made more than 5,000 arrests for clandestine photography - a record number and about three times the cases in 2010.

About seven in 10 flight attendants in Japan have also reported that their photos were secretly taken, according to a survey by a national aviation trade union published in March.

Already, most cell phone manufacturers in Japan have installed audible shutter sounds on their mobile devices, to prevent secret filming.

Several Asian countries have laws against voyeurism but enforcement varies.

In South Korea, those convicted of secretly filming images of a sexual nature face a fine of up to 10 million won (£6,000; $7,500) or a maximum prison sentence of five years.

But the Korean Women Lawyers Association said just 5% of 2,000 illicit filming cases that went to court between 2011 and 2016 resulted in jail time.

In Singapore, someone convicted of voyeurism can face up to two years in jail, fines, caning, or a combination of these penalties. Voyeuristic crimes involving victims younger than 14 years old will mean mandatory imprisonment, plus fines and caning.

Japan has been looking at several penal code changes to strengthen legislation against sex crimes, after multiple rape acquittals in 2019 caused national outcry.

In February this year, a panel of the Japanese Justice Ministry proposed raising the age of consent from 13 to 16. The statute of limitations for reporting rape will also be increased to 15 from 10 years.

The ministry's proposal also aims to criminalise the grooming of minors and expand the definition of rape.

Currently, Japan has the lowest age of consent in advanced countries, and the lowest in the G7 group.