The China Federation of Demanding Compensation from Japan (CFDC) sent a letter to the Japanese Emperor Akihito and the Japanese government on Sunday appealing for the return of a 1,300 year old stele taken from China over a century ago, the AFP reports.

According to Chinese state media the 1.8 meter tall and 3 meter wide Honglujing Stele which depicts the first king of the northeast Asian Bohai kingdom, was “looted by Japanese soldiers early last century from northeastern China,” and is now kept in “virtual seclusion” in Tokyo’s Imperial Palace. Palace grounds are open to visitors only two days a year and there is no public access to to the building where the stone monument is kept.

The CFDC, an organisation established in 2006 seeking “compensation for personal, material and spiritual damage caused by the Japanese militarism during the country’s aggression against China in the 20th century,” wants to recover “not just the relic itself, but also a symbol of international injustice” CFDC president Tong Zeng said.

The CFDC’s appeal is unlikely to have significant impact because under Japan’s constitution Emperor Akihito has no power and the imperial household and its contents is property of the state.

A spokesperson from the Imperial Household Agency declined to comment on the return of the artifact, saying “We have not received any official requests.”