Japan?s Defence Ministry is probing a suspected leak onto the Internet of navy data, including some confidential information, a ministry spokesman said yesterday.

The incident came to light a week ago when a navy inspection team spotted a message on an Internet bulletin board that suggested internal navy documents had been leaked, the spokesman said.

After a subsequent investigation, the ministry has determined that various documents, including some related to communications and training, may have been leaked, the spokesman said.

He could not confirm whether such documents in their entirety had been posted on the Internet.

?It is believed that documents that qualify as secrets were leaked,? the spokesman said, adding that an investigation was ongoing. He declined to elaborate further, but Kyodo news agency said the leaked material included cipher-related documents, and personal data.