The UN has confirmed that it has found an internal memorandum in its files which suggests that Rwanda's interim president, Paul Kagame, may have been involved in the assassination in 1994 of the former president, Juvenal Habyarimana.

Mr Habyarimana, a Hutu, was killed when the plane he was travelling in was hit by two rockets on April 6, 1994.

His assassination is believed to be the catalyst that provoked the genocide which resulted the killing of about 800,000 Tutsis and moderate Hutus.

It has generally been thought that Hutu hard-liners organised his assassination in opposition to his attempts to broker a power-sharing settlement with the then Tutsi-led rebel Rwandan Patriotic Front of Mr Kagame.

But a Canadian daily, the National Post, recently revealed that UN investigators had interviewed three unidentified members of an "elite covert strike team", who confirmed the attack had been sanctioned by RPF leader and current interim Rwandan President Paul Kagame.

The Rwandan government has rejected the accounts.

Hutu accusations

Exiled Hutu groups have frequently accused the RPF of the rocket attack on the plane.

They suggested the RPF leadership wanted to use the ensuing mayhem to seize power directly, abandoning the power-sharing agreement it had forged with the Habyarimana government.

The UN says the document was written by an Australian investigator, Michael Hourigan, who's no longer with the organisation, and was not himself sure of the veracity of his information.

"The secretariat did not find a report but a three-page internal memorandum," said UN spokesman Fred Eckhard.

"One individual committed to paper his thoughts as well as information conveyed to him and that went into a file," he added.

The UN has sent the document to the International Criminal Tribunal for Rwanda in Arusha, Tanzania, where leading Hutu genocide suspects want to use it for their defence.

The Rwandan Government has strongly denied the accounts saying the reports are propaganda by Hutu exiles seeking to revise history.