DUBAI, United Arab Emirates -- A British-Iranian woman detained in Iran while on a trip with her toddler daughter has exhausted all chance of having her five-year prison sentence overturned in court, her family said Monday.

Nazanin Zaghari-Ratcliffe is one of several dual nationals held in Iran by hard-liners in the country’s judiciary and security services on espionage charges, likely to be used as bargaining chips in future negotiations with the West.

Zaghari-Ratcliffe, who works for the Thomson Reuters Foundation, the charitable arm of the news agency, found out this weekend her final appeal to Iran’s supreme court had been denied, her husband Richard Ratcliffe said in a statement.

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Ratcliffe said he wants the British government to publicly call for Zaghari-Ratcliffe’s release, rebut the Iranian spy allegations against her and have the British ambassador in Tehran visit her in prison.

She still has not been allowed to know the exact charges for which she was convicted, Ratcliffe said.

“It is a not such a surprise that this final appeal failed. We have had two secret trials and now a closed panel review,” he said. “But it is still nonsense that even at this stage Nazanin still does not have firm details of the charges against her.”

Zaghari-Ratcliffe was arrested at the airport last year while she was with her 2-year-old daughter, Gabriella, according to Amnesty International. Zaghari-Ratcliffe had been visiting her parents in the Iranian capital.

Authorities confiscated Gabriella’s British passport and she was sent to stay with her grandparents, Amnesty International reported. She is not Iranian.

Zaghari-Ratcliffe was held in solitary confinement for 45 days before she was moved to a group cell.

Iranian news agencies have said Zaghari-Ratcliffe was convicted of plotting the “soft toppling” of Iran’s government. Her family says Iran’s paramilitary Revolution Guard tried to get her to confess on camera she trained and recruited spies, something she refused.

“I would like to reiterate that I am entirely convinced of Nazanin’s innocence,” said Monique Villa, the CEO of the Thomson Reuters Foundation. “She is not a spy but an innocent mother who travelled to Iran only to show her baby to her parents.”

There was no immediate reaction from Tehran on Zaghari-Ratcliffe. Iran does not recognize dual nationality and rarely allows consular visits to dual nationals in Iranian jails.

Among the dual nationals known to be held in Iran are Iranian-American businessman Siamak Namazi and his octogenarian father, Baquer Namazi, who are serving 10-year prison sentences for “cooperating with the hostile American government.” Iranian-American Robin Shahini is serving an 18-year prison sentence for “collaboration with a hostile government,” though he recently received bail .

Yet to be tried is Iranian-American Karan Vafadari, an art gallery manager held along with his Iranian wife. Iranian-Canadian national Abdolrasoul Dorri Esfahani, a member of the country’s team that negotiated the nuclear deal, is believed to have been indicted.

Still missing is former FBI agent Robert Levinson, who vanished in Iran 10 years ago while on an unauthorized CIA mission.