An Iranian appeals court has jailed for five years prominent activist and journalist Golrokh Iraee who has been held since her arrest at the onset of a protest movement, supporters said Sunday.

Iraee had refused to take part in the appeals court hearing over her sentence for taking part in illegal gatherings and violating national security, saying she did not recognise the legitimacy of the court, rights groups have said.

She was arrested last September in a police raid on her home at the start of the protest movement sparked by the death of Mahsa Amini who had been detained for allegedly violating the strict dress rules for women.

"Golrokh Iraee, who been in Evin prison for 280 days, was sentenced to 5 years of imprisonment" by the Tehran court, according to a Twitter account in her name run by supporters.

The court of first instance initially sentenced her to seven years in April.

Well known for her campaigns on issues including stoning sentences and prison conditions, Iraee is the wife of activist Arash Sadeghi who was also arrested during the protest movement but has now been released.

Some activists arrested during Iran's crackdown on the protest movement have been released over the past few months as the protests abated in intensity.

But prominent women campaigners remain behind bars including the prize-winning Narges Mohammadi, labour rights activist Sepideh Gholian and environmental campaigners Niloufar Bayani and Sepideh Kashani.

Meanwhile, the two women journalists who did most to expose the case of Mahsa Amini — Niloufar Hamedi and Elaheh Mohammadi, also both held since September — are on trial in Tehran on national security charges.