Two bills that would ban the import of stolen cultural assets will be submitted to the Diet ahead of the ratification of a UNESCO convention on preventing trade in such property, government officials said Thursday.

The bills will be submitted after they are officially approved by the Cabinet on Friday, they said.

They aim to prepare the way for Japan to ratify during the current Diet session the Convention on the Means of Prohibiting and Preventing the Illicit Import, Export and Transfer of Ownership of Cultural Property. The UNESCO pact entered into force in 1972 after being adopted in 1970.

One of the government bills would define and stipulate the penalties for illicit import of cultural property. Education and trade ministers would be required to consult each other after Japan is informed by overseas owners about stolen cultural goods.

The bill would extend the period when owners can seek the return of property from the current two years to 10 years.

The other bill, an amendment to the Cultural Properties Law, would stipulate that approval by the head of the Cultural Affairs Agency is necessary to export important cultural assets.

Violators would face fines of up to 500,000 yen or three years in prison under the proposed legislation.