Muammar Al-Ali knew at once that the bearded man filmed after being freed by Syrian opposition factions from a prison in Hama when the city fell to them this week was his brother, Ali, who had been missing for nearly 40 years.
"Your heart tells you this is your brother," said Al-Ali at his home in northern Lebanon.
They had not yet been able to make contact since seeing a video of him posted online on Thursday, Al-Ali said, and a Syrian journalist in Hama told them the man they thought was Ali had totally lost his memory and could not say who he was.
Ali Al-Ali was arrested aged 18 at a checkpoint by the Syrian army when it was in Lebanon during the country's 1975-90 civil war, said his family, who spent decades knocking on every door searching for him, Reuters reported.
It was all in vain, until Syrian opposition factions this week took city after city in a lighting advance, freeing thousands of prisoners from the notorious Syrian prison system.
Thousands of families now hope that they may be reunited with loved-ones held in Syrian prisons during the Assad family's half century in power.
More than 100,000 Syrians are thought to have gone missing during the country's 13-year insurgency, many of them held in prison, according to human rights groups.
Social media has been flooded with videos of Syrian detainees leaving prisons after the fall of Aleppo, Hama and Suweida to opposition, with some reunited with their families.
Around 700 Lebanese people are also thought by relatives to be held in Syria, taken during the three decades Syrian troops were in their country, many of them held for their political views.
Syrian officials have said that there were no more Lebanese prisoners in Syrian jails.
Fatima Kabbara, form northern Lebanon, said her brother Mohammed went missing in 1985, kidnapped by a Lebanese militia before being handed over to Syrian authorities.
People who have since managed to get out of Syrian detention centers told the family they had seen her brother, a father of three, at a Syrian military intelligence detention center in Damascus.
The family had never been able to locate him, but said they now hoped his fate may be uncovered.
"We want to know their destiny. If they are dead, we want their remains. And if they are alive, we want them, so our soul comes back to us," she said.
"My heart is burning for my brother."
