Natan Sharansky, now a prominent figure in Israeli politics and human rights activism, first came to international attention as a brave and defiant refusenik.

That was the name given to Russians refused permission to emigrate – especially Russian Jews seeking to leave for Israel from the late 1960s. Arkadiy Kogan’s documentary charts Natan Sharansky’s nine-year ordeal at the hands of the Soviet authorities, which began when he was arrested in 1977 on charges including high treason. It will pack an extraordinarily powerful punch at every showing, but to see the UK premiere, knowing Sharansky himself was in the audience, made it especially telling.

Filming of his return to the scenes of his imprisonment is juxtaposed with graphic footage of his separation from his family and his incarceration, including exile to Siberia, and the use of family and magazine images. Especially touching are shots of his wedding under a makeshift chuppah (wedding canopy) to Ukrainian-born Avital, a defiantly Jewish ceremony that was of course not recognised by the Soviet authorities. Dark, witty cartoons illustrating and commenting on his story make an original addition to the mix. Sharansky displays his own black humour, demonstrating a novel form of communication between prisoners via toilet bowls in adjoining cells.

This is as much the story of the supremely brave Avital, who left for Israel the day after the wedding and fought tirelessly for her husband’s release through the nine years he served of his 13-year sentence. The film salutes her resourcefulness in keeping his plight in the news, her meetings with international figures, including President Carter’s VP Walter Mondale. The climax of Sharansky’s eventual release as part of a prisoner exchange on the so-called ‘Bridge of Spies’ between East and West Berlin is as tense as in any fictional spy drama.

The screening and Q&A session with Sharansky at the BAFTA event I attended was made possible by the Genesis Philanthropy Group, whose main focuses include "strengthening Jewish identity of Russian-speaking Jews worldwide". A good fit indeed.