An Iranian women's rights activist has spoken out against Prime Minister Jacinda Ardern's decision to wear a hijab following the Christchurch mosque terror attacks.

Masih Alinejad is both an activist and journalist, and is outspoken in her condemnation of Iran's laws surrounding obligatory wearing of headscarves.

Ms Alinejad said seeing images of Ms Ardern wearing a headscarf in solidarity with the victims of the Christchurch massacre 'broke her heart'.

She said while she admired the New Zealand leader's compassion and desire to connect with her Muslim community, the headscarf is a sign of oppression for many women.

'I felt admiration that a prominent leader and women in New Zealand showed compassion to the Muslim community, but I also felt that you are using one of the most visible symbols of oppression for Muslim women in many countries for solidarity, and it also broke my heart.'

Masih Alinejad (pictured) is both an activist and journalist, and is outspoken in her condemnation of Iran's laws surrounding obligatory wearing of headscarves

After 50 Muslim worshippers were shot dead in two mosques during Friday prayers, photos of Ms Ardern paying her respects while wearing headscarves went viral

'That is why I call on them to show their sisterhood and solidarity with us, who are being beaten up, imprisoned and punished for fighting against compulsory hijab as well.'

After 50 Muslim worshippers were shot dead in two mosques during Friday prayers, photos of Ms Ardern paying her respects while wearing headscarves went viral.

Many leaders around the globe commended Ms Ardern for her quick response to the act of terror and her solidarity with victims.

But Ms Alinejad said the women in Iran are subjected to the 'discriminatory law' and urged women around the nation to remove their headscarves.

Many leaders around the globe commended Ms Ardern for her quick response to the act of terror and her solidarity with victims

She has called for women to take photos without their hijabs, which she then shares her website My Stealthy Freedom in protest of the laws.

She also told tourists who visit Iran to avoid wearing the headscarves out of 'respect for the culture of Iran,' the NZ Herald reported.

'Iranian women, they fight against the compulsory hijab and they are alone, they are on their own.

'So the female politicians who go and visit Iran, the tourists, athletes, actresses - all of them, when they go to my beautiful country they say that this is a cultural issue, we wear it out of respect to the culture of Iran.

'Let me be clear with you: calling a discriminatory law a part of our culture - this is an insult to a nation.'