leader Rios Montt's genocide conviction overturned 21 May 2013 Last updated at 05:20 Guatemala's former military leader Efrain Rios Montt has had his conviction for genocide and crimes against humanity overturned. The constitutional court said the trial must go back to where it stood on 19 April and restart from that point. On 10 May, Gen Rios Montt was convicted of ordering the deaths of 1,771 people of the Ixil Maya ethnic group during his time in office in 1982-83. The 86-year-old was sentenced to 80 years in prison. He denies the charges. Harrowing testimony The constitutional court on Monday threw out all proceedings in the case after the April day when there was a dispute between two judges about who should hear the case. In essence, the court's decision does two important things. First, it overturns the sentence of genocide against Efrain Rios Montt, at least for the time being. And secondly, it resets the legal proceedings to the point where they stood on 19 April. On that day, the court ruled, Mr Rios Montt was temporarily left without a legal defence as his lawyer was briefly expelled from the courtroom after he accused the presiding judge of bias against him. Those few hours in which Mr Rios Montt was without legal representation at his side have set back the case by over a month. All the testimonies and witness statements heard from that point onwards will have to be delivered again as will the concluding statements from both sides. The ruling follows an appeal by Gen Rios Montt's defence lawyers, who argued that procedural errors had been committed. The trial - which began in March - was beset by delays and even a temporary suspension. During the hearings, dozens of victims gave harrowing testimony about atrocities committed by soldiers. Gen Rios Montt became the first former leader to be found guilty of genocide by a national tribunal in May. Now, just days later, the jubilant scenes among indigenous campaigners in a packed court were contrasted sharply with the low-key press conference in which this latest legal twist was announced, the BBC's Will Grant in Guatemala City reports. But he adds that the decision to annul the sentence does not signal the end of the legal battle either for the prosecution or for Mr Rios Montt as both sides will now start preparing to return to court to replay the final few weeks of the trial. Mr Rios Montt's 17 months in power are believed to have been one of the most violent periods of the war. The former general abandoned politics in 2012, after serving in Congress for a number of years. He is now expected to leave the military hospital where he is currently being held and return to his home under house arrest.