Geneva, Sep 17 (DPA) Sri Lanka's probes into a video clip showing one of its soldiers executing an incapacitated man do not meet the criteria of 'impartial', a UN expert said Thursday, calling for a full investigation.

Philip Alston, the special rapporteur on extrajudicial executions, said that upon review of information handed over by the government, he could not accept Colombo's findings that the video was a fake.

The video, obtained by British Channel 4 and broadcast last month, showed a soldier, speaking the dialect of the Sinhalese majority, kicking a blindfolded and naked man in the back and then shooting him, while making jokes.

Several other bodies were seen near the executed man, and the group that located the video said they were from the Tamil minority, though the information cannot be independently verified.

At the end of the video, which is believed to have been recorded in January, a second man is shown being summarily executed.

Sri Lanka's government quickly gathered four people it said were experts to look into the video and a minister told the UN Human Rights Council in Geneva this week that the recording was 'proven' to be a fake.

The UN expert, however, said it 'is impossible to conclude that these four individuals, given their relationship to the government, meet the criteria for impartiality in this context'.