British nationals Lindsay and Craig Foreman have been sentenced to 10 years in prison in Iran over allegations of espionage.
British Foreign Minister Yvette Cooper on Thursday condemned the sentence as “totally unjustifiable”, saying the government would continue to press for their release.
Iran accused the couple of gathering information in several parts of the country.
“We will pursue this case relentlessly with the Iranian government until we see Craig and Lindsay Foreman safely returned to the UK and reunited with their family,” Ms Cooper said.
The couple, from East Sussex, have always denied the allegations. They are being held in Tehran’s notorious Evin prison.
The couple were arrested while on a motorcycle trip on January 3 last year.
Joe Bennett, Lindsay's son, said the couple had appeared at a three-hour trial on October 27 last year in which they were not allowed to present a defence.
“We have seen no evidence to support the charge of espionage,” he said. The family was deeply concerned about the couple's welfare and the lack of transparency in the judicial process, he added.
Mr Bennett on Wednesday said that US-Iranian talks in Geneva this week were also an opportunity to seek the release of Ms Foreman and other foreign detainees.
The talks concluded on Tuesday with an agreement reached on the “guiding principles” of a nuclear deal, according to Iranian Foreign Minister Abbas Araghchi, who led his country's delegation.
“For any country that engages in peace talks, hostage negotiations should also be a part of it. It shouldn’t just be peace talks [without addressing] human rights violations and hostage-taking,” Mr Bennett told The National.
Ms Foreman has admitted to “naive” mistakes when deciding to travel to the country during a motorbike world tour.
Speaking to the BBC from within the prison before the sentencing, Ms Foreman said she had travelled to Iran "as part of a global initiative to focus on the good, to focus on finding unity in humanity, and that hasn’t changed".
In a short clip broadcast on Thursday, she said: “In fact, if anything, my desire to find what connects us is even greater.”
Earlier this month, Ms Foreman spoke to ITV News by phone from the prison, telling the British broadcaster that the couple believed they had the correct documents to be in Iran, despite the Foreign Office warning citizens against travelling to the country.
Last month, Mr Bennett was joined by former Iran detainee Anoosheh Ashoori and Richard Ratcliffe, who fought a public campaign to have his wife Nazanin Zaghari-Ratcliffe freed by the Tehran regime, at 10 Downing Street to deliver a petition calling on the government to do more to free the couple.
The petition had 70,000 signatures, “which is a clear sign there is a strong belief that this is nothing but an arbitrary detention”, Mr Bennett said.
