The teenage children of jailed Iranian Nobel Peace Prize winner Narges Mohammadi fear they will never meet their mother again, but said they were proud of her struggle for women's rights as they prepared to accept the award on her behalf on Sunday.

Mohammadi, 51, who is serving multiple sentences in Tehran's notorious Evin prison on charges including spreading propaganda, won the award on Oct. 6 in a rebuke to Tehran's theocratic leaders, prompting the Islamic Republic's condemnation.

Her twin 17-year-old children, Ali and Kiana Rahman, who live in exile in Paris, are due to accept the award at Oslo's City Hall and give the Nobel Peace Prize lecture on her behalf.

In a letter smuggled out of prison and published by Swedish broadcaster SVT this week, Mohammadi said she would continue to fight for human rights even if it led to her death. But she said she missed her children the most.

Kiana Rahman, who last saw her mother eight years ago, said: "When it comes to seeing her again, personally I am very pessimistic."

"Maybe I'll see her in 30 or 40 years, but I think I won't see her again," she told a press conference via a translator. "But that doesn't matter because my mother will always live on in my heart and with my family."

Mohammadi was awarded the Peace Prize just over a year after 22-year-old Mahsa Amini died in the custody of Iranian morality police after being detained for allegedly violating the rules of wearing a hijab, an Islamic head scarf.

Amini's death provoked months of nationwide protests that posed the biggest challenge to Shi'ite clerical rule in years, and was met with a deadly security crackdown costing several hundred lives.

The Norwegian Nobel Committee said the award for Mohammadi also recognised hundreds of thousands who had demonstrated against the theocratic regime's policies discriminating and oppressing women.

Iran has called the protests Western-led subversion, accusing the Nobel committee of meddling and politicizing human rights.

Mohammadi's son Ali said he had accepted from early childhood that the family would live apart, but said he would stay optimistic he might see her again.

"If we don't see her again we will always be proud of her and go on with our struggle," he said.

Mohammadi's husband Taghi Rahmani said the award would give her a larger voice even if her own conditions were likely to become more difficult.

"It's a political prize and therefore there will be more pressure on Narges, but at the same time it is going to create a space for echoing the voice of the people" said Rahmani, who will also attend Sunday's ceremony.

Mohammadi is the 19th woman to win the prize, which today is worth 11 million Swedish crowns, or around $1 million, and the fifth person to win it while in detention.

It is awarded on Dec. 10, the anniversary of the death of Swedish industrialist Alfred Nobel, who founded the awards in his 1895 will.