Seoul (AFP) - South Korea on Tuesday urged Tokyo to remain cool-headed over a Japanese journalist charged with defamation for a story about President Park Geun-Hye as prosecutors extended a travel ban on him.
Tatsuya Kato, who until October 1 was bureau chief of the conservative Sankei Shimbun newspaper, was indicted last week on suspicion of criminally libelling Park, a charge that could see him jailed for up to seven years.
He was also banned from leaving South Korea. The prosecutors' office in Seoul said it had decided to extend the travel ban for three months from Wednesday.
Japanese politicians have made public comments criticising the indictment and last week the Japanese foreign ministry summoned Kim Weon-Jin, a minister at the South Korean embassy in Tokyo, to convey a message of concern.
On Tuesday the South Korean foreign ministry urged Japan to calm down, describing the case as a matter of law enforcement.
"I think the Japanese need to remain coolheaded," ministry spokesman Noh Kwang-Il told reporters.
"It's not proper for Japanese government officials to make unnecessary remarks because this is related to legal procedures, not a diplomatic issue between the governments of South Korea and Japan," he added.
Relations between Tokyo and Seoul are at their lowest ebb in years over disputes related to Japan's harsh 1910-45 colonial rule over the Korean peninsula.
South Korea feels Japan has not gone far enough in expressing remorse for the abuses of the colonial period or in compensating its victims.
The two main US military allies in Asia are also mired in a territorial row over a tiny batch of rocky islets in the East Sea (Sea of Japan).
Kato, 48, has been under investigation over an August 3 column about "rumours" concerning Park's whereabouts on the day a South Korean passenger ferry sank with the loss of 300 lives.
While he used some original quotes from his own sources, Kato's story was chiefly based on information already available online, and which has not been the subject of any complaint.
The story picked up rumours circulating in the South Korean media that Park was with a man at the time of the sinking.
South Korean prosecutors began questioning Kato on August 18 on complaints filed by an association of citizens.
The Sankei is one of Japan's more robust papers. It is proudly centre-right and frequently lambasts Japan's critics at home and abroad.