It’s not surprising that Mosab Hassan Yousef’s life has been turned into a film. He is the son of a Hamas founder who became a key informer for the Israelis and later converted to Christianity.

“To collaborate with Israel is the most shameful thing you can do in my culture. If somebody raped his mother, that’s very shameful. But if he collaborated with Israel, that’s much more shameful.”

So says Mosab Hassan Yousef in a documentary film, The Green Prince, which charts an unprecedented relationship between sworn enemies. For a decade Yousef put his life on the line as Israel’s most senior informer.

“Hamas was not just a movement to us – it was the family’s business, it was our identity, it was everything”, says Yousef. He was first arrested aged 10, and by his late teens he had learned to hate Israeli soldiers.

But when he was picked up for buying a gun aged 17, he was turned by the Israeli spy service Shin Bet.

Codenamed Green Prince, Yousuf claims to have prevented dozens of suicide bombings as he worked at his father’s right hand, passing intelligence to Israel.

Initially he says he had hoped to work as a double agent, but seeing Hamas’ brutality in prison, he changed his mind.

Of life in Palestine, he says “I understand the reality very well”, but declines to criticise Israel, insisting: “Israel is not only a Jewish country, it’s a democracy with all types of people.”

On hearing, in prison, of his son’s betrayal, his father disowned him. But Yousef is clear about what he thinks needs to happen to improve the situation in the region: “We need Hamas to step down and be disarmed.”