Guatemala's Constitutional Court has opened the door to amnesty for former dictator Efrain Rios Montt on charges of genocide and crimes against humanity, a judicial spokesman told Efe Wednesday.

The ruling was issued Tuesday, but has not been made public pending formal notification of the parties, the spokesman said.

The decision suggests the case against the retired general be dropped on the basis of a amnesty proclaimed in 1986 by Guatemala's then-military regime, La Prensa Libre daily said Wednesday on its Web site.

The CC, according to the newspaper, ordered trial Judge Carol Patricia Flores to rule on defense lawyers' motion for a dismissal of the charges against the 87-year-old defendant, who presided over one of the bloodiest phases of the nation's 1960-1996 civil war.

Rios Montt was convicted in May and sentenced to 80 years in prison for the deaths of 1,771 Ixil Indians between March 1982 and August 1983 as part of a counter-insurgency campaign.

But the CC threw out the conviction and ordered a repeat of the trial.

The Guatemalan Supreme Court in June rejected a motion to quash the prosecution of the erstwhile strongman, finding that the 1986 amnesty does not extend to genocide and crimes against humanity.

The retrial of Rios Montt is scheduled for April 2014.

The CC's decision is "surprising," a representative of one of the plaintiffs in the case against him, the Legal Action Center for Human Rights, told Efe Wednesday.

This year's trial of Rios Montt marked the first time any Guatemalan ruler was called to account for the massacres and atrocities of a conflict that claimed more than 200,000 lives.

Most of the dead were Indian peasants slaughtered by the army and its paramilitary allies. EFE