Japan has indicated it will not hand over to China three men accused of arranging an orgy involving hundreds of Japanese tourists.
The orgy took place in a Zhuhai hotel in September
Chief Cabinet Secretary Yasuo Fukuda said Japan would deal with the three according to domestic law.
China has issued detention warrants through Interpol, but Japan does not have an extradition treaty with China.
China on Wednesday sentenced two of its nationals to life in prison for their role, hiring 500 Chinese prostitutes.
Twelve other Chinese people were given up to 15 years jail for the incident, which took place in Zhuhai in September.
China's Xinhua news agency has named the three alleged Japanese organisers of the event as Hirobe Isao, Takahashi Shunji and Fukunaga Koji, all employees of an Osaka-based construction company.
"We cannot take them into custody simply on the basis of an Interpol request," Mr Fukuda said.
"Japanese authorities will deal with the matter according to domestic law," he said. He did not elaborate.
A spokesman at the National Police Agency said: "Japan has (extradition) agreements only with the United States and South Korea. Generally speaking, Japan's basic policy is not to extradite Japanese nationals to other nations."
Japan may have grounds to question them under its own law, however, particularly if it transpired that under-age prostitutes were involved, the Asahi newspaper reported.
The timing of the orgy sparked widespread anger in China, where many people feel Japan has failed to atone for its wartime brutality.
The orgy ended on 18 September, the anniversary of Japan's occupation of China, and many Chinese people believe it was deliberately timed to humiliate China.
The BBC's correspondent In Beijing, Louisa Lim, says postings on internet bulletin boards say that more than three Japanese should stand trial in connection with the case, and they have also renewed calls for a boycott of Japanese goods.