Argentina has requested the extradition of six men from Uruguay over the 1976 disappearance of the daughter-in law of a famous Argentine poet, Juan Gelman.
Uruguayan authorities are now studying the extradition request
The accused, five ex-military officers and an ex-policeman, have already been taken into custody in Uruguay.
Nineteen-year-old Maria Claudia Garcia was seven months pregnant when she was abducted in Buenos Aires 30 years ago.
In the 1970s, the military rulers of Argentina and Uruguay collaborated to hunt down opponents and stifle dissent.
The abduction and presumed killing of Juan Gelman's daughter-in-law remains a high-profile, unresolved case from those times, in which some 13,000 people are officially listed as dead or missing.
Argentine President Nestor Kirchner has repeatedly called for Uruguay's help in solving the investigation into Maria Claudia's disappearance, the Associated Press reports.
Maria Claudia was kidnapped at the start of Argentina's seven-year military dictatorship.
Investigators believe she was secretly taken to the Uruguayan capital, Montevideo, held until she gave birth to a baby girl, and then killed.
The military authorities in Uruguay gave the baby to a local couple to adopt.
She was reunited with her biological family after being located by Mr Gelman, one of Argentina's leading poets, nearly 25 years later.
Argentina's ambassador to Uruguay, Hernan Patino Mayer, delivered the extradition request to the Uruguayan authorities.
A statement by the Uruguayan Foreign Ministry said they had received a request to extradite the six, named as Jose Ricardo Arab Fernandez, Jose Nino Gavazzo Pereira, Ricardo Jose Medina Blanco, Ernesto Avelino Rama Pereira, Jorge Alberto Silveira Quesada, and Gilberto Valentin Vazquez Bisio.