Tokyo, April 15 (IANS): A Japanese sculptor and graphic artist accused of public obscenity for distributing 3D copies of her vagina pleaded not guilty on Wednesday in the first session of her trial.

Megumi Igarashi, 43, popularly known as the "vagina artist," admitted to the acts that led to the accusation, but insisted, as she does upon every detention, that her work was in no way obscene, Efe news agency reported.

Igarashi, who works under the alias "Rokudenashi-ko" (Absurd Girl), consistently defends her work as a tool to break taboos and fight discrimination against female sexuality in Japanese society.

Japanese law prohibits the distribution of "indecent" material, although it does not clearly define the criteria. In practice, human genitals in visual and print media, like in pornography, are censored to avoid legal problems.

Igarashi's case prompted protests throughout the world, considered a symbol for freedom of expression, while an online petition on Change.org drew thousands of signatures demanding her release.

Her lawyers insisted that the provision in the Japanese penal code was unconstitutional as it violated free speech and the right to information.

Distributing obscene material in Japan can invite a maximum sentence of two years in prison or a fine of up to 2.5 million yen ($20,900).