An Iranian filmmaker said the Islamic republic barred him from travelling to the London Film Festival over his support for the protest movement sparked by the death of Mahsa Amini that he called a "great moment in history.”

"I was prevented by the Iranian authorities from boarding my flight to London on Friday," Mani Haghighi said in a video message to festival-goers tweeted by the British Film Institute (BFI).

"They gave me no reasonable explanation for this actually rude behavior."

Outrage over Amini's death on Sept. 16, three days after she was arrested by Iran's notorious morality police, has fueled the biggest wave of street protests and violence seen in the country for years.

In response, the clerical state's security forces have waged a brutal crackdown that has claimed the lives of dozens of protesters as well as a campaign of mass arrests of artists, dissidents, journalists and sports stars.

The BFI said Haghighi had been due to attend the London Film Festival for his latest film Subtraction, but the Iranian authorities "confiscated his passport and he could not leave.”

In the video message, the 53-year-old Iranian director, writer and actor said he believed the authorities had prevented him from going abroad over his support for the Amini protest movement.

"A couple of weeks ago I recorded an Instagram video in which I criticized Iran's mandatory hijab laws and the crackdown on the youth who are protesting it and so many other instances of injustice in their lives.

"Perhaps the authorities thought by keeping me here they could keep a closer eye on me, perhaps to threaten me and shut me up.

"Well, the very fact that I'm talking to you now in this video kind of undermines that plan," he said.

Haghighi said, however, that he had no regrets about being forced to stay in Iran as a "prisoner" in his own country.

"Let me tell you that being here in Tehran right now is one of the greatest joys of my life.

"I cannot put into words the joy and the honor of being able to witness first-hand this great moment in history and I would rather be here than anywhere else right now.

"So if this is a punishment for what I've done, then by all means, bring it on."