The husband of a British-Iranian woman jailed in Iran said he fears for his wife after she developed a “cold” amid reports coronavirus had spread into the prison.

Richard Ratcliffe said conditions in the Evin prison in Tehran where Nazanin Zaghari-Ratcliffe is held have been “worsening” over the past few months.

Lack of medicine, disinfectant, bleach and antiseptic in prison shops has forced prisoners to depend on washing liquid to stay clean, while the guards enjoy a supply of essentials, he said.

The 41-year-old Ms Zaghari-Ratcliffe, who already suffers from unexplained collapses to irregular heartbeats, has a cold, a “severe” sore throat and wakes up shivering.

Writing for the i newspaper, Mr Ratcliffe said he now fears she may be at risk of contracting Covid-19, which has already claimed 34 lives in the country.

Nazanin Zaghari-Ratcliffe detained
Nazanin Zaghari-Ratcliffe. (PA)

His comments come after Commons Leader Jacob Rees-Mogg said that, while the Iranian authorities have denied any outbreak of coronavirus at the prison, he would “not always take as authoritative” such remarks.

The Foreign and Commonwealth Office (FCO) has said it remains “extremely concerned” about Ms Zaghari-Ratcliffe’s welfare.

In the piece, Mr Ratcliffe said: “On Monday we heard reports of cases, on Tuesday of a ward evacuated as a quarantine area.

“By Wednesday there were rumours of prisoners losing their life, as there had been in other prisons across the country.

“By Thursday, the judiciary was announcing plans to send eligible prisoners home temporarily.

“From far away it is hard to assess the risk calmly in Nazanin’s case – knowing we are not being told the truth is not the same as knowing what the truth is. But this week the panic grew.”

He described Iran’s initial response to the virus as a “bravado” and “a refusal to acknowledge the extent of the problem.”

Nazanin Zaghari-Ratcliffe detained
Richard Ratcliffe and the couple’s daughter Gabriella (PA/Kirsty O’Connor)

He also intensified his calls on the British Government to secure his wife’s release, saying: “Nazanin could have been released years ago, if promises had been kept. Just how far does this need to go.”

Ms Zaghari-Ratcliffe 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.

An FCO spokesman said: “The Government remains extremely concerned about the welfare of British-Iranian dual nationals detained in Iran, including Mrs Zaghari-Ratcliffe.

“We continue to raise their cases at the most senior levels. The Prime Minister has raised his concerns about dual national detentions with President Rouhani, and the Foreign Secretary with Foreign Minister Zarif.”