Britain was unsure about Japan's claim to the Senkaku Islands in the early 1970s, according to declassified documents seen by Kyodo News at the National Archives in London.
Officials were unable to establish whether Japan, China or Taiwan had a rightful claim over the small group of uninhabited islands in the East China Sea that continue to drive their bitter territorial dispute.
The advice was against making any comment on the respective claims. This position is maintained today by the Foreign Office which, when asked by Kyodo News, said it "does not take a position on the underlying sovereignty issues" and called for the matter to be resolved "peacefully and by international law."