Tokyo , Japan ( CNN ) -- A leaked video is circulating in cyberspace , showing a boat collision that sparked a recent diplomatic battle between China and Japan . The YouTube video shows the same collision that Japanese lawmakers watched on video last week , said legislator Hiroshi Kawauchi , of the ruling Democratic Party of Japan . The Japanese Coast Guard shot the video , which is authentic and not doctored , said Kawauchi , who is a member of the House of Representatives in the Diet , Japan 's legislature . `` The fact that the video was leaked is a big mistake for the government , '' he added . `` It is totally different from presenting it to the public in an official manner , and it leads the people 's further erosion of faith in Japan 's government . '' In September , Japan detained the crew of a Chinese fishing boat off disputed islands in the East China Sea . China calls the islands the Diaoyu ; Japan calls them the Senkaku . In response to the detainments , China made increasingly aggressive diplomatic threats . Beijing also halted ministerial-level talks with Tokyo , and both sides canceled trips to each other 's nations . Japan has since released the fishing crew , who China says were stopped illegally . Japan initially accused the captain of obstructing Japanese public officers while they performed duties . But authorities later said that releasing him was in the interest of maintaining relations with China . The crash video that Japanese lawmakers saw has not been released to the public . The video , posted on YouTube , shows what is thought to be the Chinese fishing trawler ramming into a ship , thought to be a Japanese Coast Guard vessel . The Chinese government dismissed the video after Japanese lawmakers saw it , saying it had been edited and that it did not change the ownership of the islands . On Friday , China 's Assistant Minister of Foreign Affairs Cui Tiankai said : `` I think the China-Japanese relationship has to overcome the current difficulties and move forward . This will serve the fundamental interests of both countries . So [ we ] hope [ the ] Japanese side will do everything possible to make sure that there 's no further disruptions of the relationship . '' The Chinese Embassy in Tokyo has contacted the office of Japanese Prime Minister Naoto Kan about the leaked video , making an `` official inquiry , '' Kan 's office said . No official protest was lodged . Kan 's office is investigating the leaking of the video , which has been shown on Japanese television . The man apparently doing the videotaping says on the video that the date is September 7 , 2010 . That matches the detaining of the fishing crew . The man also says on the video , in Japanese : `` We 've ordered them to stop , in Chinese language , but they did n't stop . '' As the Chinese boat approaches , shouting is heard in Japanese . Unidentified voices shout : `` Stop , stop ! '' CNN 's Jo Ling Kent contributed to this report .
The YouTube video is authentic and not doctored , a Japanese legislator says . He calls the leak `` a big mistake for the government '' China has made an `` official inquiry '' with the Japanese prime minister 's office . Kan 's office is investigating the leaking of the video .