Image copyright Sherry Izadi Image caption Sherry Izadi with her husband Anoosheh Ashoori

The wife of a British-Iranian dual national who has been jailed for 10 years in Iran says allegations he was a spy for Israel are "bogus".

Anoosheh Ashoori, a 65-year-old retired civil engineer from London, was convicted in July of spying for Israel's Mossad intelligence agency.

His wife, Sherry Izadi, said the claims were "preposterous" and asked the UK government to help free him.

The British Foreign Office has urged Iran to reunite him with his family.

Speaking for the first time since his arrest, Ms Izadi told the BBC her husband had been visiting his 86-year-old mother in Iran in August 2017 when he was "bundled into a car" by Iranian authorities.

She said the father of two had been held in solitary confinement on and off for four months.

Image copyright Sherry Izadi Image caption Anoosheh Ashoori (pictured with his daughter and his wife) is a retired civil engineer from London

Image copyright Sherry Izadi Image caption Mr Ashoori has "never been involved" in politics, his wife says

Ms Izadi, 56, said her husband was forced to represent himself at his trial and that his appeal has been rejected.

Mr Ashoori, a civil engineer, was also handed a two-year term for illicitly acquiring money and fined $36,600 (£29,850). Ms Izadi said it was unclear whether the two sentences were to run concurrently or not.

"He is 65, he is not young, and being away for 25 months-plus and being stuck in a basement prison in conditions that are far from ideal... it takes its toll on families," Ms Izadi said.

"The thought of him staying there for 10 or 12 years, and he'll come out a 75-year-old man, is just unimaginable and inconceivable," she added.

Ms Izadi said her husband was "the most un-political person imaginable".

"He has never been privy to any state secrets and we just lived extremely ordinary lives," she said.

"My husband has never worked for any government sectors, he has never been involved in any political dealings, he never had any political affiliation."

Image copyright PA Media Image caption Boris Johnson called for the release of another British-Iranian detainee during a meeting with Iran's president earlier this week

Iran has detained a number of dual citizens and foreign nationals in recent years, many of them on spying charges.

The Iranian authorities do not recognise dual nationality for Iranian citizens and do not grant consular access for foreign diplomats to visit them in detention.

Ms Izadi has launched a petition calling on the UK government to take action to help free her husband.

A spokesperson for the British Foreign office said it strongly urged Iran to reunite British-Iranian dual national Mr Ashoori with his family.

"Our Embassy in Tehran continues to request consular access and we have been supporting his family since being made aware of his detention," a statement read.

"The treatment of all dual nationals detained in Iran is a priority and we raised this issue in margins of the UN General Assembly yesterday."

The response comes after Prime Minister Boris Johnson called for the release of a detained British-Iranian woman during a meeting with Iran's president.

Mr Johnson invited President Hassan Rouhani to London to discuss the case of Nazanin Zaghari-Ratcliffe.

Mrs Zahgari-Ratcliffe - a mother-of-one from Hampstead - is half-way through a five-year jail term after she was convicted of spying in 2016, which she denies.

Media playback is unsupported on your device Media caption Why one mother's personal plight is part of a complicated history between Iran and the UK (video published August 2019)

Ms Izadi said her now-retired husband's liberty was being "sacrificed" in the ongoing diplomatic spat between the UK and Iran.

"His crime is that he's a dual national, that he holds a British passport," she said. "That's not right."

Tensions between the UK and Iran have worsened in recent months following a row over the seizure of oil tankers in the Gulf.

Relations strained further on Monday after the UK, France and Germany agreed that Iran was responsible for the attack on Saudi oil facilities on 14 September.

Iran denied responsibility, accusing the three countries of "parroting absurd US claims".

Image copyright Sherry Izadi Image caption Ms Izadi has launched a petition to try to help her husband

This week, UK Foreign Secretary Dominic Raab described Iran's "arbitrary detention of dual nationals" as "unlawful, cruel and totally unacceptable".

He said the cases had been raised by himself and the prime minister with Iran's president and foreign minister.

But Ms Izadi said the government should "go beyond talks and smiles" and instead "take action".

The BBC has contacted the Iranian Embassy in London for comment.