The bearded men in plainclothes who grabbed Ali from a crowd of anti-regime protesters and hauled him to a nearby mosque had no idea who they had arrested.It wasn't until the regime thugs had finished beating him and the 50 or so other young men they had rounded up that they checked his identity papers.
Then, when they realised that Ali Karroubi, 36, was the son of Mehdi Karroubi, a leader of Iran's opposition Green Movement, they started beating him again - this time with sticks and batons.
"When they recognised who my brother was, the militia tried to punish him so badly," said Mohammed Taghi Karroubi, the reformist politician's eldest son.
"His wrist was fractured, he received so many lashes on his back and legs and his internal bleeding was so bad he was vomiting up blood. He was tortured by the basij and the police for five or six hours before they released him."