The Tokyo District Court decided Tuesday to ask the Metropolitan Police Department to confirm whether Prime Minister Yoshiro Mori was caught in a brothel more than four decades ago, as claimed by a monthly magazine involved in a libel suit.
The libel suit was filed by Mori over an article printed in the June edition of Uwasa no Shinso (Truth of the Rumor).
The magazine has said it stands by the article and has asked the court to check police detention records to prove it.
Mori's lawyers asked the court to reject the request, saying whether their client was detained by police over 40 years ago is a purely private issue.
However, presiding Judge Koichi Shinano said Tuesday that the issue was a matter of public interest and decided to make an inquiry with Tokyo police.
The article says that Mori was detained on suspicion of violating the antiprostitution law in 1958 while he was a 20-year-old student at Tokyo's Waseda University.
Mori, now 63, said the story is groundless and filed the suit in May, demanding the magazine take out advertisements apologizing for the article and pay him 10 million yen in compensation.
One of the lawyers defending the magazine said: "It is unusual for a court to make inquiries about criminal records, which is the greatest privacy. Police may refuse to respond because there is no punishment for not cooperating with court requests. However, we hope police will respond."