A Japanese media outlet said Tokyo has approved a Seoul-bound shipment of one of three key industrial items that became subject to tightened restrictions last month.

Japan's Sankei Shimbun daily said on Thursday that after a "strict review," Tokyo approved a Japanese exporter's request to send a shipment of what are reported to be photoresists, a material used in the production of semiconductors, to a South Korean firm on Wednesday.

The approval is the first since Tokyo tightened restrictions on exports of fluorinated polyimides, photoresists and etching gas to South Korea on July fourth.

The export curbs are widely believed to be retaliation for political disagreements with Seoul over colonial-era issues, but Tokyo at the time cited national security concerns as the reason behind the restrictions.

The right-of-center daily said Japan's Shinzo Abe administration plans to expand the list of export items that require case-by-case approval should it find any "improprieties" regarding management of exports to South Korea.