The late anti-apartheid hero was known for preaching against the white-minority regime in South Africa, which ended in the 1990s. He often spoke at the funerals of activists killed by the state’s security apparatus.
Ms Tutu said she was shown a video of a funeral on the outskirts of Johannesburg in July 1985, where mourners were mercilessly beating and kicking a defenceless man as he lay on the ground, curled up in a fetal position.
The man was doused with petrol and moments away from being “necklaced”, a term used to describe having a tyre placed around your neck and then set alight, when Mr Tutu and other clergy stepped in to push back the mob.
She said: “To see that and to see him going in – there were so many things that were striking about it.
“One was that he had the courage to go into the crowd and say: ‘No, this is not how we do it.’
“But the other is that those young people listened, right, that there was a dignity in our struggle that these young people, they could have said: ‘Who are you to tell us about these people who are selling us out.’
“But there was still that respect for who did it and the other clergy that, you know… Here are clergy people who are asking us to step back from this action.”
She added: “That is my proudest moment, that whenever I think what made me proud of Daddy, that is the thing that I always go to.”
Mr Tutu had been accused of being an apartheid collaborator at a time when South Africa was in a state of emergency and banned liberation parties.