Japan on Thursday denied a foreign media report that it made political donations of over €1 million to the International Atomic Energy Agency over the planned release of treated water from the Fukushima No. 1 nuclear plant into the ocean.

The report is "groundless" and "the Japanese government strongly opposes such irresponsible dissemination of false information," the Foreign Ministry said in a press release.

The rumor about the donations linked to the planned water release from Tokyo Electric Power Company Holdings' plant, the site of the March 2011 triple meltdown, started spreading after a South Korean online media outlet published a story on the matter, according to a ministry source.

The media report was based on a document from an unknown source that included comments by a person described as a senior ministry official to the effect that Tokyo made the political donations to settle disagreements among the Japanese government, the IAEA and third-party country experts.

The report quoted the person as saying in the document that the conclusion of the IAEA's upcoming final report was decided from the beginning, with the safety of the water release plan set to be declared.