The current genocide trial against ex-Guatemalan dictator Efrain Rios Montt was dropped Thursday in a surprise legal move, but a judge is likely to launch fresh proceedings, officials said.

The development, blamed on procedural technicalities, will delay public deliberations over events that have divided the country for 30 years.

The 86-year-old retired general, who insists he was not aware the army was committing massacres, is accused of ordering the execution of 1,771 members of the Ixil Maya people in the Quiche region during his 1982-1983 regime.

If convicted, he could face five decades behind bars.

The genocide trial would be the first of its kind arising from the 36-year civil war, which pitted leftist guerrillas against government forces and ended in 1996, leaving an estimated 200,000 dead or "disappeared," according to the United Nations.

Rios Montt's attorney Francisco Palomo told AFP that the trial was completely "tainted" due to "legal aberrations to rush" the process.

"He had an order to end the trial as soon as possible and issue a conviction to get (Rios Montt) in the general prison," Palomo said of the judge who had presided over the latest proceedings.

But Edgar Perez, a lawyer for the plaintiffs, said the move "leaves the victims defenseless and violates their fundamental right to justice."

Although the current proceedings were scrapped, Judge Carol Patricia Flores said she had been ordered by the Supreme Court and the Constitutional Court to pick up the case again.

"The proceedings are being canceled," she said. "I am not doing this because I want to but because it has been ordered by the Constitutional Court and the Supreme Court" due to a pending legal ruling.

Flores was initially in charge of the trial but was recused from the case by defense lawyers over claims of bias.

Judge Miguel Angel Galvez then took over pre-trial proceedings in November 2011, and ordered the public trial against the former dictator. Those proceedings began in March.

Flores must now set a date to decide, once again, whether Rios Montt should face a public trial.

The court had ordered Rios Montt, who is under house arrest, to appear at every hearing along with retired general Jose Rodriguez, a former member of the military leadership who is on trial with him and housed in a military hospital.

Rios Montt was known for his "scorched earth" campaign against people the government branded leftist rebels, but who were often indigenous Mayans not involved in the conflict.

The trial was seen as a historic step in a country with such high impunity that most crimes go unsolved. (AFP)