Daniel Craig's latest film Defiance tells the powerful story of three Jewish brothers who fled the Nazi occupation of their Polish town, set up a partisans' camp in dense forest and fought back.

But the film has provoked controversy over whether the Bielski brothers, who helped more than 1,200 Jews to escape from the ghettoes, were courageous heroes or ruthless killers who, fighting alongside Soviet partisans, committed atrocities against ethnic Poles.

Now Jack Kagan, who as a 14-year-old boy escaped from his prison camp to join the fighters in the forest, has spoken out in defence of the three brothers – Tuvia, played by Craig, Zus (Liev Schreiber) and Asael (Jamie Bell) – who carried out the largest armed rescue of Jews by their own people during the war.

Mr Kagan, 79, who attended the premiere of the film which opened on Friday, said in an exclusive interview with The Sunday Telegraph:"The brothers were heroes. They saved my life and so many others. Without them we would all have been killed.

"They were much more concerned with saving Jews than with killing Nazis. They did not kill innocent people," Mr Kagan said at his home in Hampstead, northwest London, where he lives with his 77-year-old wife Barbara....