Japan's top government spokesman yesterday declared himself dumbfounded after a recent prime minister said he understood China's claim to islands at the centre of a bitter row between Tokyo and Beijing.
Yukio Hatoyama, a left winger whose brief term as premier was almost universally regarded as a flop, told Hong Kong-based Phoenix Television it was "unavoidable" that China believed Japan "stole" the Senkaku islands.
The uninhabited outcrop in the East China Sea, which Beijing claims as the Diaoyus, is the subject of a decades-old dispute that has flared badly in the last year. Both countries continue to send official ships to the area to press their ownership.
Japan says it brought previously unclaimed islands under its control in 1895. China says they were illegally snatched and should have been returned alongside other occupied territories after the second world war.
During the interview, which was broadcast in China on Tuesday, Hatoyama said: "It is unavoidable that the Chinese side thinks Japan stole" the islands.
As a media storm gathered, he told Japanese reporters later in the day that he had meant to say there was "a possibility" that China might think that way.
Japan's chief government spokesman, Yoshihide Suga, said Hatoyama's comments were "outrageous".
"I was completely at a loss for words when I heard about his remarks. It was literally jaw-dropping," he told a news conference this week.
"It is outrageous and unforgivable that a former prime minister has said things that hurt our national interests," Suga said.
Asked again on Wednesday about the episode, Suga said he had still not recovered his tongue.
"I said yesterday that I was left open-mouthed. I still remain so."
Despite the regular stand-off between official vessels at the islands, Japan's stated position is that there is no dispute over the archipelago.
Hatoyama, who led the now-opposition Democratic Party of Japan and served as prime minister between September 2009 and June 2010, has left politics, but as heir to the Bridgestone tyre empire he still remains active in business circles.
His time in office was marked by confusion and policy flip-flops, including on the US military presence in Okinawa, which managed to alienate voters and irritate Washington without achieving any drawdown of American troops.
Earlier this year, his visit to the Nanjing Massacre Memorial, which marks the scene of one of the Japanese Imperial force's worst wartime atrocities, caused consternation at home when he said he felt "responsibility" for the outrage.