Nazanin Zaghari-Ratcliffe has appeared in court in Iran and has been told she will face another trial on Sunday, an MP has said.
Iran's state TV reported on Tuesday that the British-Iranian dual national was facing a new charge, citing an unnamed official.
Labour MP Tulip Siddiq later said she had spoken to Mrs Zaghari-Ratcliffe, confirming that she had appeared in court on Tuesday morning.
Ms Siddiq tweeted on Tuesday: "I've been in touch with Nazanin Zaghari-Ratcliffe and can confirm that she was taken to court this morning and told she will face another trial on Sunday.
"I know many people are concerned about her welfare and I'll keep everyone updated when we have more information #FreeNazanin."
Mrs Zaghari-Ratcliffe was granted temporary release from prison this spring following the coronavirus outbreak after serving nearly all of her sentence.
I've been in touch with Nazanin Zaghari-Ratcliffe and can confirm that she was taken to court this morning and told she will face another trial on Sunday.
I know many people are concerned about her welfare and I'll keep everyone updated when we have more information #FreeNazanin
— Tulip Siddiq (@TulipSiddiq) September 8, 2020
She was arrested at Tehran's Imam Khomeini airport while travelling to show her young daughter, Gabriella, to her parents in April 2016.
She was sentenced to five years in prison over allegations, which she denies, of plotting to overthrow the Tehran government.
She was later afforded diplomatic protection by the UK Government, which argues that she is innocent and that her treatment by Iran failed to meet obligations under international law.
It has been claimed Mrs Zaghari-Ratcliffe is being held in order to force the UK into settling a multi-million pound dispute with Iran.
The debt dates back to the 1970s when the then-shah of Iran paid the UK £400 million for 1,500 Chieftain tanks.
After he was toppled in 1979, Britain refused to deliver the tanks to the new Islamic Republic and kept the money, despite British courts accepting it should be repaid.
Her husband Richard Ratcliffe said last month there was "clearly a stand-off" between the two countries, and that he feared his wife could face a second court case once her sentence comes to an end next spring.