Residents of Madagascar's tourist island of Nosy Be went on the rampage on October 3rd, 2013 after the body of an eight-year-old local boy, who had been missing for a week, was found on a beach.
Incensed by false rumours of foreign involvement and a paedophilia connection, a mob attacked Sebastien Judalet, a French tourist, and Roberto Gianfalla, a Franco-Italian resident of the island, and beat them before burning them on a beach.
The uncle of the dead boy was also killed and burned later the same day.
The judge adjourned the case on Tuesday because two police officers charged in connection with the slayings failed to appear in court.
The two officers are accused of failing to intervene to prevent the attack.
Their lawyer said they had not received a summons to appear in court.
The other defendants are accused of premeditated murder, illegal confinement, torture and disturbing the peace.
Famous for its white pristine sandy beaches and turquoise waters, Nosy Be is Madagascar's main tourist magnet, but has been plagued by sex tourism.
"We've been waiting for this trial for two years," said Andre Randranto, an attorney for one of the victims, said.
Mob justice is common on the vast island nation off southeast Africa, which authorities struggle to police effectively.