Does the state have the right to force a person to find out who their real parents are? Does a grandmother have the right to find a grandchild born in a secret interrogation centre and given away by her birth mother's tormentors?

This is the debate that is raging in Argentina 27 years after the end of the country's Dirty War, in which the military dictatorship detained and killed an estimated 30,000 people.

The "Grandmothers of the Plaza de Mayo" was formed 33 years ago with the aim of finding an estimated 500 babies who were stolen from their imprisoned and subsequently murdered mothers.

The group's goal has been to reunite the disappeared children with their biological families.

Since the advent of a DNA bank a decade ago, the "Grandmothers" have located about 100 children who were adopted illegally and identified as the offspring of disappeared political prisoners.

Some of the encounters with their biological families have been happy ones.

Maria Eugenia Zampallo was not only happy to find her biological family but sought to punish her "fake" parents by taking them to court. She won: they were sentenced to life in prison for abducting a stolen child.

But for others, finding out the truth has been tragic. In one case, a young adopted man was encouraged to find out about his origins. After testing his DNA, he discovered that he was the son of a disappeared political prisoner. But by doing so, he unwittingly brought attention to the couple who had brought him up and whom he loved as parents. They were sent to prison for illegally adopting a stolen child.

That is why many are now reluctant to find out the truth. 

In the meantime, time is running out for the grandmothers, who are dying of old age.

But now with the help of the current government, they are waging an even more aggressive campaign to recover their grandchildren and to punish those who in the majority of cases knowingly took a child who already had a family.

Chicha Mariani is one of those grandmothers. She believes that Marcela Noble Herrera, one of two adopted children of Argentina's richest and most powerful woman could in fact be her granddaughter, Clara Anahi, who was taken by police along with her mother when she was three months old.

The case of Marcela and Felipe Noble Herrera, now both 34 years old, has opened up a Pandora's box of ghosts from the past and charges of political persecution in the present.

They are the heirs of Ernestina Herrara de Noble, the owner of the nation's most powerful media conglomerate, the Clarion Group, which is now at war with the Kirchner government.

The Noble Herrera siblings claim President Kirchner is trying to use them to punish their adopted mother.

But a new law now gives the police the power to force suspected "grandchildren" to give DNA samples.

While the Noble Herrera siblings are fighting the law in court, it is just a matter of time before they will be forced to take the DNA test and compare it to those of thousands of women who were kidnapped and murdered after giving birth to children, who were then stolen.

This drama unfolds on many levels; legal, emotional, ethical and political. Does a grandmother's search for the truth justify destroying, in many cases, the lives of children who are now adults and do not want to be found? Is justice an end in itself, no matter how late?

Lost and Found can be seen from Tuesday, August 17, at the following times GMT: Tuesday: 0600, 1930; Wednesday: 1430; Thursday: 0030; Friday: 0830; Saturday: 2330.