An empty seat on the Cannes festival jury

The Cannes Film Festival opens today, but come Friday one seat on the prestigious Cannes jury panel will be empty. Acclaimed film director Ja’far Panahi was due to join the jury panel, chaired this year by Tim Burton, but he is detained in Tehran's Evin Prison, following his arrest on 1 March for making a film about last year’s disputed presidential election.

Another Iranian film-maker, Mohammad Ali Shirzadi, is detained in the same prison, apparently for filming an interview between a human rights defender and a prominent dissenting cleric, Ayatollah Montazeri.

Both of the men are prisoners of conscience, locked up for the peaceful expression of their political views. We’ve launched an Urgent Action appeal for their immediate and unconditional release.

Earlier this month, Hollywood heavyweights Steven Spielberg, Martin Scorsese, Robert De Niro, Robert Redford, Francis Ford Coppola, Joel and Ethan Coen, Ang Lee, Michael Moore and Oliver Stone signed a petition urging the Iranian government to release Ja’far Panahi, who has made internationally-acclaimed films such as The White Balloon, Offside and The Circle.

Today, the French government spoke up too: "He is one of the most eminent representatives of Iranian film and his place is at the festival where he has been invited as a member of the jury," said Foreign Minister Bernard Kouchner and Culture Minister Frederic Mitterrand in a joint statement.

He was arrested on 1 March, along with his wife, daughter and several other guests at his home in Tehran. The others have since been released and his wife was allowed to see him for the first time on 30 March.

Mohammad Ali Shirzadi was arrested by five unidentified men on 4 January 2010 outside his home in Tehran. His computer, notebook and other personal items were confiscated.

As the rest of the world’s film-makers gather in Cannes to celebrate freedom of artistic expression, the Iranian authorities continue to isolate themselves and deny Iranian citizens the rights enjoyed by so many others around the world. Iran has a strong and proud artistic tradition, not least in the medium of film: I’m looking forward to a screening of “Nobody knows about Persian Cats”, an indie film about Tehran’s underground music scene, that we’ll be showing here at Amnesty’s Human Rights Action Centre later this year. It’s a shame that in culture as well as in politics, the Iranian authorities continue to clamp down on those it perceives as critics.