Barbie and Peter Reynolds, whose family had voiced serious concerns over their health and their ability to survive Taliban custody, were detained by the group's interior ministry on February 1.
Qatar was in talks with Taliban authorities for several months, in coordination with the British government and the couple's family, to secure their release, the official said.
"Throughout their eight months in detention - during which they were largely held separately - the Qatari embassy in Kabul provided them with critical support, including access to their doctor, delivery of medication, and regular communication with their family," the official added.
Afghanistan "does not view issues related to citizens from a political or transactional perspective," Qahar Balkhi, the spokesperson for Afghanistan's foreign ministry, said on social media platform X.
He added the couple violated Afghan laws, without giving details.
Richard Lindsay, Britain's special envoy to Afghanistan, speaking to Sky News, thanked Qatar and said the couple were very happy when asked about their state.
He said he was not clear on what grounds they were held.
"It's obviously up to the authorities here to determine why they were detained, but we are very grateful that at least, today is a very great humanitarian day, that they will be reunited with their family," he said.
Afghan authorities arrested four individuals - two British nationals, one Chinese-American and their interpreter, a spokesperson for the interior ministry told Reuters at the time.
The BBC, citing official Taliban sources, reported in February that two British nationals believed to be working for a non-governmental organisation in the central Afghan province of Bamiyan had been detained. It cited one official as saying they had been arrested after using a plane without informing local authorities.
The couple were arrested alongside a Chinese-American friend, Faye Hall, and a translator from their training business, Britain's PA news agency reported.
Qatar has worked to secure the release of foreigners detained in Afghanistan since the Taliban came to power in 2021. The Gulf Arab state's negotiators have helped to secure the release of at least three Americans so far in 2025.
Western countries, including Britain and the United States, shut their embassies and withdrew their diplomats as the Taliban took over Afghanistan in 2021.
