A court in the capital, Antanarivo, has sentenced former president Marc Ravalomanana and two officers to life imprisonment with hard labour for the part they played in the deaths of about 30 protesters before he was forced from office in 2009.
Ravalomanana, who has lived in exile in South Africa since being deposed by the country's current leader, Andry Rajeolina, with the help of the miltary, has been convicted twice before by other courts.
Observers believe this third court ruling is aimed at preventing his return to contest the forthcoming presidential elections and warned this might jeopardise any chances the country has for a dialogue on breaking the current political impasse.
After deliberations, the court which conducted the latest trial admitted the testimony of witnesses who said Ravalomanana gave orders to shoot if protestors approached the presidential palace during a demonstration.
Lawyers for the former leader have, however, rejected the decision, saying it is valueless. They refused to take part in the case, saying they had petitioned the higher courts several weeks previously and were waiting for a decission from them.
Ravalomanana reacted by telling the international press it was a "stupid and ridiculous" judgement to which he gave no particular importance.
He said it was a political manoeuvre aimed at preventing him from participating in elections and hindering talks currently taking place.
Rajeolina on his part said in a radio and television broadcast that "there is an end to everything" and that the country should now focus on the upcoming elections.
He said he had told judiciary he respected their independence. He also announced a national conference from September 13 to 18 and said he intends to propose a new constitution in the comming days.
A group of Malagasy citizens living in France have condemned the court ruling, maintaining that only the high court is competent to handle a case of that nature.
Observers have suggested that the trial will hinder the peace process and undermine negotiations initiated by civil society.
Compiled by Michael Tantoh from reports in Midi Madagasikara.