Hundreds imprisoned by the military junta vanished or were killed in the period. The Grandmothers of the Plaza de Mayo has campaigned for years for the identities of those who disappeared to be made public.
Now brother and sister Marcel and Felipe Noble Herrera, heirs to a media fortune seem to have run out of ways to block forced DNA testing to determine their origins.
The Herrera children have argued that the search for the truth about their biological mother amounts to an invasion of their privacy and they have attempted to halt it. If the courts establish that their ageing adoptive mother received them illegally she could be convicted and sent to prison.
"Our identity is ours. It's a private thing and I don't think it's up to the state or the Grandmothers to come and tell us what is ours," Ms Herrera said. Speaking to the Associated Press, she added: "There is not a single concrete fact showing that we were taken from the junta's imprisoned enemies."
"If it is really true, well, it's up to us to assimilate it. It's up to us to prepare ourselves and it's up to us to see what we want to do. Only we will know how we'll feel."
Her brother attempted to play down the significance of the DNA tests, however. "Whatever the result, for me it's just one more sheet of paper, one more fact in my desk," Mr Herrera said