The family of Britons Craig and Lindsay Foreman, who have been detained in Iran, said the situation was causing “significant concern”.
They were reportedly detained in January but Iran’s state-run media revealed this week they had been accused of security-related offences.
The couple were reportedly traveling around the world on motorbikes when they were held.
A statement from the family said: “We would like to take this opportunity to address the distressing situation concerning Craig and Lindsay Foreman who are currently being detained in Kerman, Iran.
“This unexpected turn of events has caused significant concern for our entire family, and we are deeply focused on ensuring their safety and well-being during this trying time.
“We are actively engaging with the British government and relevant authorities, working diligently to navigate the complexities of this matter.
“The family are united in our determination to secure their safe return.”
The duo were ultimately heading for Australia, having crossed into Iran from Armenia on December 30, according to social media posts.
Mrs Foreman is carrying out a research project as part of the journey, asking people what constitutes a good life.
The couple had shared a number of updates from the Middle Eastern country, and had been planning to enter Pakistan next.
“To put your minds at rest, we are having the most amazing time in Iran,” they posted on Facebook on January 3.