Cavallo's lawyers finally lost the battle against extradition
Mexico's Supreme Court has ordered the extradition to Spain of a former Argentine navy officer to face charges of genocide and terrorism.
Ricardo Cavallo was arrested in the southern Mexican resort of Cancun in 2000 after a newspaper report said that five former political prisoners had identified him as their torturer.
A Spanish judge, Baltasar Garzon, has accused Mr Cavallo of human rights crimes during Argentina's 1976-1983 military dictatorship.
The Mexican Supreme Court decision - which is not subject to appeal - ends a three-year battle to extradite Mr Cavallo.
Judge Garzon argues that Mr Cavallo tortured prisoners at the Argentine Navy Mechanical School, one of the most notorious centres of repression during the country's "dirty war".
His extradition to Spain was made possible under the principle of universal jurisdiction, which allows human rights atrocities committed in one country to be subject to criminal prosecution by courts in another.
The ruling delighted Argentine human rights activists
The ruling was hailed by the US-based campaign group Human Rights Watch as "a real victory for international justice".
"Mexico will become the first Latin American country to extradite someone for gross human rights violations under the principle of universal jurisdiction," said Jose Miguel Vivanco, who heads the group's Americas division.
Mr Cavallo says he was in Argentina's military at the time but he has denied involvement in any human rights abuses.
Up to 30,000 people were killed or "disappeared" during the Argentine military government's campaigns against leftist opponents.
The Supreme Court judges unanimously threw out the charge of torture, arguing that too much time had passed to prosecute Mr Cavallo on that charge.
According to the indictment, Mr Cavallo belonged to a special unit that was actively involved in kidnapping and torturing people.
Court documents implicate him in the torture of Thelma Jara de Cabezas and the execution of Monica Jauregui and Elba Delia Aldaya, the AFP news agency reports.