In 1964, athletes taking part in the Tokyo Olympics brought with them seeds from their homeland to be planted as commemorative trees.

More than 50 years later, Japan is now searching for the whereabouts of these arboreal legacies as it prepares to host the Tokyo Olympics and Paralympics in two years' time.

Records kept at the National Land Afforestation Promotion Organization (NLAPO) show some 270 species from over 40 nations were brought in exchange for native species and that the organization requested arrangements for the swift processing of the seeds at customs.