The last of Argentina's military rulers, Reynaldo Bignone, has been arrested as part of an investigation into human rights abuses.
Mr Bignone denies any involvement (photo: La Nacion Archive)
He is being held at a military base where a secret detention centre was set up during the 1976-83 military regime.
Mr Bignone, who became president in 1982, has denied any involvement in the disappearance of dissidents.
Human rights groups say some 30,000 people died or "disappeared" during what became known as the Dirty War.
A judge is expected to question Mr Bignone, 79, on Friday in connection with crimes committed at the secret prison set up in the Campo de Mayo base.
The secret detention centre, outside Buenos Aires, is said to have been the largest in operation during the Dirty War.
It is said to have been the scene of thousands of cases of torture and killings.
The judge will also consider a request from the former ruler's lawyers that he be held at home rather than at the base.
Mr Bignone is also awaiting trial in connection with the stealing of babies from political prisoners, an accusation he has described as an "invention".
During military rule, many children and babies were taken from prisoners and given for adoption to military or police couples.