A trial has begun for 16 defendants in the Republic of Congo for their alleged role in the massacre of more than 300 Congolese refugees in 1999. But the trial is being boycotted by three human-rights groups that first brought the case to light in France.

There is still no trace of the bodies of 353 people who were allegedly killed in 1999, shortly after returning from exile in the neighboring Democratic Republic of Congo. But French human-rights groups say there is no doubt that the so-called Beach massacre, named after a riverside town in the Republic of Congo, took place.

Six-years later, a court in Brazzaville is trying 16 men, including high-level Congolese officials who were allegedly involved in the killings. The Republic of Congo says the trial, which is to be broadcast on television, will be fair and transparent. But French lawyer Patrick Baudoin denounces the trial as a sham.

Mr. Baudoin is the former president of the Paris-based International Federation for Human Rights. The human-rights federation was invited to be a plaintiff in the Brazzaville trial. But he says there is no chance of a fair trial, and participating would simply give it a veneer of justice.

The International Federation was one of three human-rights groups to bring the so-called Beach massacre to court in 2001, but in France, not in the Congo. They charged the highest Congolese officials were implicated in the disappearances and killing of the 353 people, all of whom were suspected opposition members during Congo's brief civil war.

Lawyer Baudoin says their case is buttressed by the testimonies of six alleged survivors, who have refugee status in France.

Mr. Baudoin says its very likely that Congolese President Denis Sassou Nguesso knew about the killings, but did nothing to stop them. At the time, Mr. Sassou Nguesso had told political opponents who had fled Congo they could return safely home. Congolese authorities have denied wrongdoing.

In 2004, a French appeals court annulled the judicial proceedings, started three-years ago in Paris. Mr. Baudoin says the court's reason was that the charges had been filed against an unnamed party, instead of specifying a particular defendant. Carrying on the trial, he says, would also have created diplomatic difficulties for the French government.

The human-rights groups have appealed the French court's decision. They are waiting for France's highest Court of Cassation to rule whether or not they can renew their charges about the Beach killings, but in a French court, not a Congolese one.