Two British-Australian women are being held in Iran at the notorious prison where mum Nazanin Zaghari-Ratcliffe is jailed, say reports.
One of the woman, is a blogger who is travelling through Asia with her Australian boyfriend, was arrested 10 weeks ago, says The Times.
The other, an academic in Australia, has been given a 10-year sentence although her charges are unclear.
The arrests come art a time of growing tensions between London and Tehran and an ongoing attempt to free jailed Nazanin.
The 41-year-old, who is of dual British-Iranian nationality, has been held on spying charges, she strongly denies, since 2016.
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Although it is not known what charges the academic has been found guilty of, a 10-year term is typical for spying charges, reports say.
The latest two cases are believed to be the first imprisonments in Iran of British passport holders who do not also have Iranian nationality.
The arrests come amid a downturn in relations between Britain and Iran, sparked by issues including the seizure by the Royal Marines in July of an Iranian oil tanker near Gibraltar.
The blogger and her boyfriend had been documenting their travels on YouTube and Instagram.
Concerns were raised by their online followers when they failed to add any news posts in the past several weeks.
The Foreign and Commonwealth Office referred the PA news agency’s request for comment to the Australian Department of Foreign Affairs and Trade, which has yet to respond