The Japan Coast Guard and prosecution authorities concluded Saturday that video footage of recent collisions between a JCG vessels and a Chinese trawler leaked to the Internet was authentic.
They said their investigation into the leaking of the footage of the Sept. 7 collisions showed the leaked footage was identical to one of a dozen video files that the JCG office on Ishigaki Island, Okinawa Prefecture, submitted to the Naha District Public Prosecutors Office in the prefecture.
The footage leaked to YouTube, totaling about 44 minutes in length and comprising six clips, exactly matched a file prepared by JCG officials for submission to prosecutors as evidence, the officials said.
However, there were subtle differences between the original and leaked video clips in subtitles explaining what was happening at the time of the collisions, according to the officials.
As the differences could lead to identification of who first posted the video clips on the video-sharing Web site shortly after 4 p.m. Thursday, investigators were conducting a thorough and detailed analysis of the leaked video footage, they said.
Prosecution sources said the differences might have occurred when the person or persons responsible for the leak split the original footage into the six clips.
The prosecution authorities, meanwhile, said they had concluded their analysis of video recordings on Internet servers at the Naha District Public Prosecutors Office, Fukuoka High Public Prosecutors Office and the Supreme Public Prosecutors Office in connection with the video footage in question.
The JCG and prosecution authorities said their investigation of prosecutors and assistant prosecutors who downloaded the same video files as the leaked ones using their respective servers at the three prosecution offices showed no evidence of any unauthorized access to or downloading of the files.
The Naha District Public Prosecutors Office, after receiving the collision footage from the Ishigaki Coast Guard Office and putting it into the the office's exclusive server, had the servers at the high and supreme prosecution offices upload the footage as evidence in preparation for possible court proceedings involving the captain of the trawler that rammed the JCG vessels, district prosecution officials said.
Viewing the video footage via the servers is impossible without inputting an authorized ID and password.
No more than three or four people at the Supreme Prosecutors Office and the Fukuoka High Prosecutors Office, respectively, were authorized to view the footage. About 10 people at the Naha District Public Prosecutors Office were authorized to do so, the authorities said.
They said a group of prosecutors charged with investigating the leak will continue their probe, with a view to officially announcing the results early this week.
On Saturday morning, the JCG dispatched two additional officials from its headquarters in Kasumigaseki, Tokyo, and the Yokohama-based No. 3 regional JCG head office to the Ishigaki Coast Guard Office to bolster an investigation into how the video footage was stored.
The JCG headquarters sent four officials on Friday to the Ishigaki office to look into circumstances surrounding the leak.
The officials in charge of the probes were analyzing access records for the computer at the Ishigaki office on which original video footage was edited into about a dozen files for investigation purposes, according to officials at JCG headquarters.
Of about 130 officials working at the Ishigaki Coast Guard Office, the PCs and related belongings of about 10 personnel engaged in the investigation of the Senkaku collisions were examined Saturday, the JCG headquarters said.