Japanese police have arrested a Tokyo artist on obscenity charges for distributing data that allowed recipients to make 3D prints of her vagina, sparking protests over what supporters said was an attack on free expression.

Megumi Igarashi, 42, who calls herself Rokude Nashiko, which roughly translates as "bastard kid", had been trying to raise funds online to pay for the construction of a kayak.

Megumi Igarashi in her vagina kayak.

In exchange for donations, she supplied data to supporters that would let them create 3D prints of her genitals.

Japan has a notoriously vibrant pornography industry that caters to a vast array of tastes. But obscenity laws still forbid the depiction of actual genitalia, which usually appear censored or pixellated in images and videos.