MEXICO CITY , Mexico ( CNN ) -- The Mexican Supreme Court has ordered the release of 20 people who were convicted in the massacre of 45 people in 1997 . Mexican Mayan Indian massacre survivors reenact the killings of 45 people in Acteal village in this 2003 photo . The court ruled that authorities obtained evidence illegally and that the defendants were denied due process and lacked an adequate defense . The 20 were convicted for taking part in a massacre in the community of Acteal , in the southern state of Chiapas . Four of five Supreme Court justices decided Wednesday to order their immediate release , the court said in a statement . `` It 's obvious that the evidence was obtained illegally , '' said Judge Jose de Jesus Gudino . Investigators say 45 men , women and children were killed in Acteal by people who suspected they had links to the Zapatista Army of National Liberation , a group that launched a rebellion against the Mexican state in January 1994 . It was nearly four years after that rebellion , on December 22 , 1997 , that the 45 unarmed indigenous peasants were massacred in Acteal . Then-President Ernesto Zedillo ordered an investigation that eventually led to arrests . In addition to ordering 20 people released , the Supreme Court called for the review of cases involving six others who were convicted in the massacre . Judge Juan Silva Mesa decried the judicial process that led to the convictions . `` For me there is no greater injustice than allowing them , under and in the name of the law , to commit injustice '' and thereby `` affect someone 's fundamental human rights , '' he said . CNN 's Mario Gonzalez contributed to this report .
Mexican high court orders release of defendants convicted in 1997 killings of indigenous people . Court rules evidence seized illegally , defendants denied due process . Unarmed indigenous men , women and children massacred in state of Veracruz . Killers thought Indian peasants had ties to Zapatista Army of National Liberation .