Cult victims died in France, Switzerland and Canada

Sixteen of the bodies were found in France, sparking a lengthy inquiry which led to Mr Tabachnik's trial.

But in a written judgement, the judges concluded: "The evidence and the cross-examinations have not uncovered sufficient proof, beyond hypotheses" that Mr Tabachnik had deliberately helped set up the killings.

The judges also threw out three civil suits brought by relatives of the victims.

Mr Tabachnik, 58, had been accused of "participation in a criminal association", an offence which carried a maximum sentence of 10 years.

Following the verdict, Mr Tabachnik's lawyer Francois Szpiner told reporters: "Michel Tabachnik explained himself before the judges. He had confidence in them and he was right to do so. This brings to an end my client's long suffering".

Redemption mission

Prosecutors had argued that Mr Tabachnik took part in two crucial meetings in 1994, at which the decision was taken to end the sect's "mission" and wind up its affairs.

They said Mr Tabachnik played a role in conditioning cult members to believe they were in an elite group with a mission of redemption.

Co-founder Luc Jouret was among the dead

Eleven days after the second meeting, 48 cult members were found gassed or shot in Switzerland. Others were found dead in fires in Canada.

The following December, 16 more charred bodies - including those of four children - were found, this time in a forest in the French Alps.

All had been shot in the head, and laid out in a star formation in a forest clearing.

A French judge who investigated the deaths decided that two cult members killed the others and then themselves, but some relatives believe the perpetrators did not die and are still at large.

Ideology

The 74 dead cult members included founders Luc Jouret and Joseph di Mambro, who had allegedly taken money from their followers before convincing them they had to die by burning in order to reach the afterlife.

Prosecutors had argued that Mr Tabachnik had close links with di Mambro, drawing up documents defining the sect's ideology.

But Mr Tabachnik insisted that he himself had been among those exploited by di Mambro.

Mr Tabachnik studied under Pierre Boulez and became famous as a conductor specialising in contemporary music, holding orchestral posts in Canada, Portugal and France.