The latest audiotape statement attributed to Osama bin Laden is not authentic, according to a Swiss research institute.

The Lausanne-based Dalle Molle Institute for Perceptual Artificial Intelligence said it was 95 per cent certain the tape does not feature the voice of the long-absent terrorist leader.

US experts say the tape may never be fully authenticated because of its poor quality, but those who have heard it generally support US law enforcement officials' conclusion that it probably is bin Laden speaking.