The couple, who originally met at the University of Bath, married in Kabul in 1970. Since 2009 they have been running training projects in five schools in Kabul and one project in Bamiyan training mothers and children.

While the Taliban’s return to power in August 2021 saw most of their staff leave – along with most westerners – Mr and Mrs Reynolds insisted on staying put.

After their arrest, the couple were initially able to keep in touch with their four children by text message. The family knew that their parents were being held by the interior ministry and were assured by them that they were “fine”.

Three days later, however, the texts stopped. The children have heard nothing since.

Ms Entwistle, who lives in Daventry, Northamptonshire, told the BBC: “It’s been over two weeks since the messages stopped, and they were taken into custody.

“We would like the Taliban to release them to go back to their home and continue their work.”

She told the Sunday Times, external: “They said they could not leave when Afghans were in their hour of need.

“They were meticulous about keeping by the rules even as they kept changing.”

Their daughter told the Times: “My mother is 75 and my father almost 80 and [he] needs his heart medication after a mini-stroke. They were just trying to help the country they loved. The idea they are being held because they were teaching mothers with children is outrageous.”

The couple were arrested alongside their American friend Faye Hall and a translator from their business, the PA news agency reported quoting an employee.

The employee, who described the pair as “the most honourable people I have ever met”, said Mr Reynolds had been denied access to heart medication and his condition was “not good”.