A British-Iranian charity worker held in Tehran for six years called on Monday for all "unjustly detained" prisoners in Iran to be freed, speaking publicly for the first time since her release.

Nazanin Zaghari-Ratcliffe thanked everyone involved in the campaign to secure her release but added: "What's happened now should have happened six years ago... I shouldn't have been in prison for six years."

She was speaking in her first news conference since being released from Iran last week along with another UK-Iranian national, Anoosheh Ashoori. Their families both believe they were held as political prisoners over an unresolved debt.

Zaghari-Ratcliffe also spoke of the "very emotional moment" she was reunited with her husband Richard, and seven-year-old daughter Gabriella.

A British-US national, Morad Tahbaz, remains in Iran where he is being detained in a hotel and his family have told the BBC that he is "absolutely distraught" and fears he will be forgotten about. 

The British government last week settled a historical resolved a £394-million ($515-million, 470-million-euro) debt dating back to the 1970s and the era of the Shah of Iran. 

Zaghari-Ratcliffe said she had been "a pawn" in the hands of two governments since she was arrested in Tehran on a visit to family in 2016.  She had worked as a project manager for the Thomson Reuters Foundation, the philanthropic arm of the news and data agency.

"I don't think anybody's life should be linked to a global agreement," she said. "Every human has the right to be free."