When he was released in 1955, he went into exile in Mexico. Before he left, however, my mother met up with him and fell pregnant. He wanted her to join him in Mexico, but she still had her other family to think of. The thing is, Castro is the sort of person who feels betrayed by the smallest thing, so although she wanted to be with him, he took a step back from her. I came to realise later that Castro doesn't like emotions: he thinks they make you weak and vulnerable. I was then born and named Alina, after his mother, Lina. She was a tough woman.

After another failed attack on Batista in 1956, Castro and the other rebels fled into Cuba's Sierra Maestra mountains to prepare for the revolution. When that came, in January 1959, I was three. One of my first memories of Castro is seeing him on TV, coming down from the mountains. My mother was still living with my stepfather, but they had separate lives, and in 1964 he and my stepsister fled to the US. Like anyone leaving Cuba, they were called traitors.

After that, Fidel started visiting the house and taking care of things more. But it wasn't until I was 10 that my mother told me Castro was my father. He'd always visit at night time, in his uniform and his boots. I remember the smell of his cigar. We had a very tender relationship. We'd play games like balls and pins, and he'd bring me back a doll or a piece of porcelain or a garment when he went to places like Russia. He also liked cooking and would sometimes give us recipes. But it wasn't like he was always there to tell me bedtime stories or help me with my homework.

But then his feelings for my mother began to change and we saw less of him. Although she remained totally truthful to the revolution, as I got older I wasn't convinced. His regime controlled everything and I felt that in the creation of his new society, Cubans were guinea pigs. The fact that Fidel was my father was irrelevant. I basically had the same life as everyone else. Of course, when I did see him, I'd speak to him about all the shortages and injustices in Cuba, but he just said what he wanted to say, and in the end I knew they weren't the kind of conversations he wanted with me. He could be very charismatic, very agreeable, but at the end of the day he was a political animal — hard and pragmatic. For him, you were either a fundamentalist or you weren't — there was no in-between. If you weren't part of the revolution, you were the enemy.

As his daughter, expectations of me were high — to be the best speaker, the best sportsperson, the best student. I wasn't. I studied at the School of Medicine, but I didn't get a degree. When I was 17, I got married. I actually got married four times and Castro didn't always approve — though he liked No 2 because he was an Angolan war hero.

As time went by I wanted to leave Cuba, but the authorities wouldn't let me, so I became a public dissident. By my mid-twenties, my relations with Castro had become so difficult, I didn't want contact with him at all. And by the time my own daughter, Alina, was 16, I felt I had to offer her an alternative life, so I decided to escape. I got a falsified passport, disguised myself as a tourist and flew to Madrid, then the US. It caused a huge media stir, which pressured Castro into allowing Alina to join me.

Castro has eight children altogether, from three women. My stepfather, who'd fled Cuba, died before I could see him again. His daughter lives in Virginia. They, like a lot of Cubans whose families were split by the revolution, suffered a lot. We are a suffering generation. It's been tough for me, but I'm not sad; I don't get emotional about my father.

I've since become involved in human rights because I think what's going on in Cuba is awful. And, regrettably, my father is responsible for it. He is 78 now and has been in power for almost half a century. It would be beautiful if he could prepare his country for democracy, but I don't think he will. Then again, with him, you can expect anything.

A documentary, Castro, is on the National Geographic Channel tonight at 11pm