A British couple who had been on a motorcycle tour around the world were detained in Iran, Britain’s foreign office said on Saturday.

The couple, Craig and Lindsay Foreman, were last heard from on social media in early January. But this week, Iranian state media reported that two British nationals had been detained on suspicion of “security crimes.”

Britain’s foreign office confirmed their detention after the Iranian reports, and on Saturday issued a statement on behalf of the couple’s family.

“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,” the family said.

Mr. and Ms. Foreman, both in their mid-50s, were on a motorcycle tour to Australia, where Ms. Foreman, was set to deliver a paper at a conference on psychology. They reside in Spain, where Ms. Foreman worked as a psychologist and life coach and Mr. Foreman as a carpenter.

The couple’s detention first came to light when Iranian state media published a photograph of Britain’s ambassador to Iran, Hugo Shorter, meeting with two British citizens accused of “security crimes.”