Jafar Panahi, whose films have won awards at several European film festivals, was arrested in July even before the start of the wave of protests that has rocked the Iranian regime since September.
Despite hopes for his release last month, Jafar Pahani remains imprisoned in Evin prison in Tehran.
"Today, like many people trapped in Iran, I have no choice but to protest this inhumane behavior with what I hold most dear: my life," he said.
"I will refuse to eat and drink and to take any medicine until my release," said the filmmaker, whose hunger strike began on February 1.
“I will remain in this state until, perhaps, my lifeless body is released from prison,” he added.
Jafar Pahani, 62, was arrested on July 11 and served a six-year prison sentence handed down in 2010 for "propaganda against the system".
But on October 15, the Supreme Court overturned the conviction and ordered a new trial, raising hopes for his lawyers' release.
Jafar Panahi won a Golden Lion at the Venice Film Festival in 2000 for his film "Le Cercle".
In 2015, he was awarded a Golden Bear in Berlin for "Taxi Tehran", and in 2018 he won the Best Screenplay award at the Cannes Film Festival for "Three Faces".
His arrest in July came after he attended the court hearing of another director, Mohammad Rasoulof, who was arrested days earlier.
The latter was released from prison on January 7 after being granted a two-week leave for health reasons.
Film personalities are among thousands arrested in Iran in a crackdown on protests sparked by the death in custody of Mahsa Amini, a young Iranian Kurd arrested for allegedly breaking a strict dress code for women.
Actress Taraneh Alidoosti, who posted images of herself not wearing an Islamic veil, was among those detained before being released in early January after nearly three weeks in detention.
© 2023 AFP