Animal charity operated by an ex-marine in Kabul is being examined by the United Kingdom Charity Commission.
The regulator is looking into the funding arrangements of Operation Ark, which raised more than £200,000 from supporters in days.
Operation Ark was launched by Pen Farthing's charity Nowzad to evacuate staff members and their immediate families, plus the animals in its care.
The charity says it acted correctly.
Nowzad, which reported income of close to £1 million last year, told reporters: "The trustees are wholly confident that Nowzad's life-saving work in incredibly difficult circumstances was both the right and only thing to do and was absolutely in furtherance of the charity's purpose."
The Charity Commission contacted Nowzad for further information after receiving reports around the governance and financial arrangements of Operation Ark.
It is examining the use of charity funds for the evacuation and whether it is in line with the charity's purpose.
"We will assess the information provided by the trustees to determine whether or not there is a role for the Commission," it said in a statement.
Nowzad operated an animal clinic, dog and cat shelter and donkey sanctuary in Afghanistan. It trained and employed local Afghans as vets.
As the Taliban takeover progressed last month it said its staff were in danger due to their work with foreign organisations, such as embassies, and "the animals were at risk because the Taliban considers companion animals, particularly dogs, unclean."
The former Royal Marine and his supporters led a evacuation campaign which garnered a lot of public attention. It received huge public support but also came in for criticism, including from Defence Secretary Ben Wallace who complained it distracted from focusing on evacuating the most vulnerable.
The charity says an "extremely fraught but ultimately successful" evacuation ensued.
It says "all staff and their families, including young children and two newborns, and 162 dogs and cats have been delivered to safety."
Nowzad confirmed the Charity Commission is asking for their trustees' comments on Operation Ark including, specifically, how it furthered the charity's purpose.
"The trustees of course recognise that it is entirely proper for the Commission to gather more information regarding this high-profile and unprecedented operation and are very happy to provide the information requested," it added.
Nowzad is a registered charity in England and Wales and is regulated by the Charity Commission.