Actors Emma Thompson, Penelope Cruz, Kate Winslet, Ian McKellen and directors Ken Loach and Mike Leigh were among a host of luminaries to sign an open letter demanding the star of "The Salesman" be freed.
"As members of the international arts community, we demand the immediate release of Academy Award-winning actress, mother and activist Taraneh Alidoosti, who was arrested on 17 December 2022 and has been taken into custody at Evin prison, Iran, where many other political prisoners also remain," the letter says.
Alidoosti, 38, was arrested on Saturday, official media said, after making a string of social media posts supporting the protest movement -- including removing her headscarf and condemning the execution of protesters.
The actor is one of the most prominent figures arrested in a crackdown by Iran's hardline regime that has seen the detention of lawyers, cultural figures, journalists and campaigners.
"The Iranian authorities have strategically chosen to arrest Taraneh before Christmas to ensure her international peers would be distracted," the letter continues.
"But we are not distracted. We are outraged. Taraneh Alidoosti, like all citizens of Iran, has a right to freedom of expression, freedom of association, and freedom from arbitrary arrest and detention.
"We hereby stand in solidarity with her and demand her immediate release and safe return to her family."
The Islamic republic has been shaken by protests since Amini's September 16 death in custody after her arrest by the morality police for allegedly violating Iran's strict dress rules for women.
At least 14,000 people have been arrested since the nationwide unrest began, the United Nations said last month.
The United States on Tuesday condemned Alidoosti's arrest as "part of the regime's effort to sow fear and suppress these peaceful protests."
The open letter comes after "The Salesman" director Asghar Farhadi took to Instagram to demand Alidoosti's freedom.
Alidoosti appeared in two of Farhadi's earliest films before he won international renown, "Beautiful City" (2004) and "Fireworks Wednesday" (2006).
She then appeared in the 2009 film "About Elly," which earned Farhadi the Silver Bear for best director at the Berlin film festival, before reuniting for "The Salesman" in 2016.
"The Salesman" won an Oscar for Best Foreign Language Film in 2017.
