The Swiss foreign ministry said the country’s federal administration officials had met Abbt in Benghazi and she had received medical care.

“She is doing well under the circumstances and is currently on her way back to Switzerland,” it added.

Federal Councillor Ignazio Cassis thanked those involved in her release, adding that he was “relieved that [she] is free again after more than a year and a half”.

The government said it had established a task force – including the foreign affairs department, police and other agencies – after the kidnapping became known.

It added that Switzerland had maintained regular contact with Austria from the outset.

Earlier, Libyan officials were reported as saying the women would be handed over to authorities in their respective countries after necessary procedures were completed.

Libya’s al-Masar TV showed the two women entering what looks like an ambulance and later being attended to by a health worker.

Speaking in French, the women thanked Khalifa Haftar, military commander of eastern Libya, and his son, Saddam Haftar, for their release.

Gretzmacher was an aid worker who had lived for many years in Niger, while Abbt had spent several years living and working as a community worker in Agadez.