The UN has sought a fresh probe into alleged war crimes against Sri Lankan troops after Britain's Channel 4 News released a video featuring soldiers executing naked men and women.
The video, which was broadcast on Tuesday, shows government troops executing civilians in the last few weeks of the 26-year Sri Lanka war, which ended last year when the island government declared victory over the Tamil rebel group LTTE.
"It is shocking indeed, and clearly deserves more investigation," Christof Heyns, the UN Special Rapporteur on extrajudicial, summary or arbitrary executions, was quoted as saying by Channel 4 News.
In the video, a soldier is seen to shoot one of the blindfolded prisoners in the leg as he lies amongst the bodies of other Tamil prisoners on the ground. The soldier is then seen to walk away and turns directly to the camera.
His image is briefly out of camera shot behind another soldier before he appears again close to camera - his face and moustache clearly visible.
The video then shows what appears to be a Sri Lankan soldier dressed in camouflage shooting another prisoner directly in the head. This would appear to be an execution.
The video is a longer version of one which already sparked a UN investigation 16 months ago when it first came to light. Channel 4 News has sent the new video to the UN panel investigating allegations of war crimes in Sri Lanka.
The Sri Lanka High Commission in Britain had denied that the videos broadcast by Channel 4 News were authentic.
In a statement, it told Channel 4 News: "The High Commission of Sri Lanka categorically denies that the Channel 4 News TV video is authentic.
"Last year when Channel 4 News telecast a similar video the government of Sri Lanka clearly established, by reference to technical considerations, that it was not genuine but fake. The present video is nothing more than an elongated version of the same video."
The statement said: "It is observed that there is a common pattern in these sinister moves. Some sections were replete with photographs of alleged war crimes when Sri Lanka's application for the extension of GSP+ facility was being considered by the European Commission."