Thousands of disappearances and killings committed during Guatemala's civil war may be judged in Spanish courts after a change in the law.
Rigoberta Menchu wants Guatemalan abuses investigated
Spain's highest court ruled that cases of genocide committed abroad could be judged in Spain even if no Spanish citizens have been involved.
The ruling follows a request by a Guatemalan Nobel prize winner for Spain to probe abuses in the 1970s and 1980s.
The decision overruled a rejection of the request by Spain's lower courts.
The Constitutional Court ruled that: "The principle of universal jurisdiction takes precedence over the existence or not of national interests.
"Spain should investigate crimes of genocide, torture, murder and illegal imprisonment committed in Guatemala between 1978 and 1986."
Around 200,000 people were killed during that time, according to the case filed by Nobel peace prize winner Rigoberta Menchu, a campaigner for indigenous rights.
In 2003, the Supreme Court narrowly rejected the request saying the alleged genocide of native Indians by the then Guatemalan regime was not tied to Spanish national interests.
The Constitutional Court said that ruling violated Mrs Menchu's basic legal rights.
Spanish courts have tried international cases before, but they have involved Spanish victims.
Earlier this year, former Argentine naval officer Adolfo Scilingo was convicted in Spain of crimes against humanity and given 640 years in prison.
He was found by a court to have been on board planes from which 30 people, including a number of Spaniards, were thrown to their deaths during the military rule.
Under a similar law, two Rwandan businessmen were jailed by a Belgian court for war crimes and murder during the 1994 genocide. But in Belgium, those charged must be living in the country.