Sri Lanka has dismissed as fake a new documentary to be shown on British television on Tuesday, alleging atrocities were committed in the final weeks of the island\'s war with Tamil rebels. The defence ministry in Colombo said the videos, to be broadcast publicly for the first time on Channel 4, were a fabrication and cited a forensic video analyst on its web site as saying that they were extensively edited. The footage was shown privately to the UN Human Rights Council in Geneva earlier this month and has been available on the web sites of a number of Tamil lobby groups and human rights organisations. What appeared to be the same images were also shown by Al-Jazeera television in November. The Doha-based channel said it obtained the images from an unnamed Tamil source who said they had been taken by a member of Sri Lanka\'s military. Channel 4 last December broadcast a five-minute video of the bodies of women in a muddy field and said they were killed by government forces. The footage was an extension of another video shown by the broadcaster in 2009 in which troops appeared to shoot two blindfolded men. Sri Lanka has persistently rejected the footage as a fabrication to discredit its army. Army chief Lieutenant General Jagath Jayasuriya this month offered to probe \"specific allegations\" of war crimes. The island nation\'s government has previously maintained that no civilians were killed by its troops and there was no need for an investigation. The UN has said up to 7,000 civilians were killed in the final months of fighting when government forces crushed the Tamil Tiger leadership in a no-holds-barred military offensive that ended in May 2009.