The law prohibits commercial sex with children under 18, and restricts the sale and distribution of child pornography.

It also prevents Japanese tour operators from organising sex tours abroad.

Under the new law, those who pay for sex with children can be punished with a fine of up to one million yen ($8,200) or a prison sentence of up to three years.

Previously, Japanese law only banned sex for money with those 13 or younger.

Criminal complaint

The new law also eliminates a previous requirement that victims under 13 must file a criminal complaint with the police before rape charges can be made.

However, the often explicit drawings in so-called "manga" comics are not covered by the law to "respect freedom of expression."

Correspondents say the vote follows growing international criticism that Japanese inaction on sex tourism and Internet child pornography was allowing the crimes to persist at home and abroad.

UN convention

Interpol says 80% of the world's child pornography comes from Japan.

The new legislation was approved by the Japanese upper house last month and Tuesday's unanimous vote by the 500 members of the powerful lower house means that it now becomes law.