A former Argentine political prisoner and her son have met for the first time since she gave birth in the cell of a clandestine detention centre in 1976.

Mario Bravo was given for adoption to a non-communist family, a common practice during the military dictatorship.

He was reunited with his mother, Sara, by campaign group Grandmothers of the Plaza de Mayo, after taking a DNA test.

"My mother is alive and that is a miracle," he said at an emotional press conference in Buenos Aires.

Most pregnant militants arrested by Argentina's secret police were killed shortly after giving birth.

Mr Bravo was brought up in the north-eastern province of Santa Fe.

He decided to take a DNA test in 2007, after having doubts about his identity.

His DNA was compared with a bank of genetic samples collected by the Grandmothers from families searching for their children.

'Black-and-white film'

The Grandmothers of the Plaza de Mayo was formed to reunite families with their missing children, who had been stolen by the military junta, which was in power in Argentina from 1976-83.

"I saw my life pass through my mind like a black-and-white film," he said at the group's headquarters.

"We now have to be positive, to think ahead," he added.

"What happened was very ugly, but it's done."

His mother, Sara, lived in fear for decades in the northern province of Tucuman after being released from prison, the Grandmothers said.

She preferred not to have her surname disclosed.

Mario Bravo is the 119th child to be identified by the Grandmothers.

The announcement was made on Monday and he said he counted the hours and minutes until he met his mother on Tuesday morning.

"This comes to show that we need to have faith in ourselves and in the other," said the founder and president of the organisation, Estela de Carlotto.

She was reunited with her grandson, Guido, last year.

Some 30,000 people are estimated to have been killed during more than seven years of military rule in Argentina.