A special investigation by Channel 4 featuring devastating new evidence of alleged war crimes in Sri Lanka is screened at the UN Human Rights Council in Geneva, as pressure mounts for action.

The documentary is an hour-long investigation into the final weeks of the bloody Sri Lankan civil war and features damning new evidence of war crimes and crimes against humanity.

Titled Sri Lanka’s Killing Fields, Jon Snow presents the investigation which was shown to the United Nations Human Rights Council on Friday.

Disturbing footage in the film includes the apparent extra-judicial massacre of prisoners by government forces, the aftermath of targeted shelling of civilian hospitals and the bodies of female Tamil fighters who appear to have been sexually assaulted.

Also examined in the film are atrocities carried out by the Tamil Tigers, including the use of human shields, and footage depicting the aftermath of a suicide bombing in a government centre for the displaced.

The UN screening was attended by a number of ambassadors from nations including the US and UK.

A Sri Lankan delegation also attended. It was the first time they had seen the new alleged evidence of war crimes and crimes against humanity.

Sri Lanka’s Killing Fields will be broadcast on Channel 4 on 14 June.

War crimes claims

In a world exclusive, Channel 4 News first broadcast the footage allegedly showing Sri Lankan government forces shooting dead bound prisoners in August 2009.

Last November, a second video of the same massacre emerged, revealing the naked dead bodies of at least seven women. The faces of some of the government troops could also be seen.

Following an investigation, Channel 4 News identified of one of the female victims in the video as a high profile member of the Tamil Tiger communications team. A potential date and location of the massacre was also determined.

Earlier this week, a UN special envoy said the footage appeared to be evidence of “serious international crimes”.

The Sri Lankan government has consistently rejected the footage as falsified.

As the UN says it will continue its investigations, pressure has increased on the Sri Lankan authorities to allow an international inquiry into allegations that thousands of civilians were killed at the end of the 26-year war.

UN report

In April a 200-page report commissioned by UN Secretary-General Ban Ki-Moon concluded that up to 40,000 civilians may have died in the final push by the government to defeat the Tamil Tigers.

The UN report found credible evidence that both sides of the conflict committed serious war crimes. The report called for an international inquiry – that call has so far has gone unheard.

The Secretary-General said he lacked the authority to personally order an investigation into the mass killings.

A spokesman for Ban Ki-Moon said that without the consent of Sri Lanka’s government ,or a decision by the UN Security Council, General Assembly, Human Rights Council or other international body, Ban will not move to set up a formal investigation of the civilian deaths.

UN officials concede that Colombo would never consent to such an investigation of its conduct in the conflict.

Sri Lanka has acknowledged some non-combatants were killed in the war, but says the numbers have been inflated by LTTE supporters.