The Venice Film Festival left a symbolic empty place for Iranian filmmaker Jafar Panahi on Friday as his latest movie got its world premiere while he languishes behind bars in Tehran.

The director, who has won multiple international awards, was imprisoned along with two other filmmakers in July in the latest crackdown on civil society.

But his new film, "No Bears", competing for the top prize Golden Lion in Venice, shows that the many years of trying to silence Panahi have done nothing to curb his searing political critique and wry sense of humour.

The film is partly focused on Iranians in Turkey, trying desperately to emigrate to Europe.

But it also follows Panahi himself in a fictionalised version of his real life, as he struggles to make the film from across the border in Iran, which he was already banned from leaving.

One of the film's stars, Mina Kavani, told reporters in Venice that she was inspired by his focus, despite having to direct by phone and internet.

"He was in such concentration, he had such perfectionism -- as an actress, I couldn't let myself get sentimental," said Kavani, who lives in exile in France.

"All that counted for him was cinema. He just wanted to make his movie. I thought: 'I know now why he's Mr Panahi.'"

- 'Survival' -
 

In 2010, Panahi was sentenced to six years in prison for "propaganda against the system" following his support for anti-government protests.

As can often happen in Iran, the sentence was never carried out but hung over him -- and was only enacted in July when he went to enquire about two other filmmakers, Mohammad Rasoulof and Mostafa Aleahmad, who had just been arrested.

Panahi and Rasoulof issued a defiant statement via the Venice organisers last week, vowing to continue making art.

"The history of Iranian cinema witnesses the constant and active presence of independent directors who have struggled to push back censorship and to ensure the survival of this art," they wrote.

Panahi won the top prize at the 2015 Berlin Film Festival for "Taxi", and best screenplay at Cannes for "Three Faces" in 2018 -- but was unable to accept either prize in person.

The crackdown on civil society has worsened even further under President Ebrahim Raisi, an ultra-conservative former judiciary chief who came to power last year.

Yet Iran's independent filmmakers continue to punch above their weight, in spite of the pressure.

A second Iranian film is competing for the Golden Lion this week -- "Beyond the Walls" by Vahid Jalivand -- a grim look at Iran's security state and those trapped within it.

Jalivand was cautious in his words at a press conference on Thursday, saying "a balance between the two sides" was needed in Iran today.

"In this movie the hero of the movie is a security official himself. We have unfortunately reached a perspective where it is totally bipolar," he told reporters.

"If we can create the sense of brotherhood, dialogue will become much easier, there will be less violence. This is my true belief and I would still believe this even if I were living in Europe or the United States."