He is under house arrest, has been banned from leaving Iran and is prohibited from making films for 20 years. But that did not stop Jafar Panahi appearing at the Karlovy Vary film festival in the Czech Republic last night – via Skype.

Panahi, who has found other ingenious ways around the restrictions on his freedom in the past, is showing his latest film Closed Curtain at the festival. His daughter Solmaz has been presenting it in his absence, as both the drama's co-director, Kambuzia Partovi, and star, Maryam Moqadam, had their passports confiscated in the wake of Closed Curtain's debut at the Berlin film festival in January.

Panahi's film (also known as Parde) is about a group of people trapped in a house by a lake, a predicament critics have suggested represents a thinly veiled critique of the repression suffered in Iran by the film-maker and other artists. Both its directors appear in front of the camera. The movie, which won the Silver Bear for best screenwriting in Berlin, was shot at Panahi's villa on the Caspian sea and smuggled out of the country. Eric Kohn of IndieWire labelled it "less a finished movie than a cry for help", adding: "its enigmatic trajectory allows viewers to empathise with Panahi exclusively through his ideas."

In his Skype appearance, the director thanked festival organisers for helping him meet fellow film-makers while visiting the event in 2001 for a retrospective of his films. "Unfortunately I have lost that family, but my heart is with you," he said. "It is very painful for me to not be a part of society, because I make film about society … And now I live in an absolute world of melancholy."

Closed Curtain is the second movie Panahi has made (following 2011's This Is Not a Film) since his ban. That earlier film was smuggled out of Iran on a USB stick inside a cake and went on to be nominated for a best documentary Oscar.