face mask faulty
© Christoph Schmidt/picture alliance via Getty Images
A man wearing a FFP2 respirator on a train in Stuttgart, Germany, on April 15, 2020.
Fifty million face masks bought by the UK government for frontline healthcare workers are being recalled because the straps aren't tight enough.

The FF2 respirators were supplied to the National Health Service (NHS) by Ayanda Capital as part of a £252 million ($331 million) deal, signed in April, to provide personal protective equipment (PPE) to health workers, court documents show.

However, the government has said that the masks use fastenings around the ears rather than the head, meaning they may not fit tightly enough, the BBC reported.

The deal was brokered by Andrew Mills, a businessman and adviser to the UK Department for International Trade, who also sits on the board of Ayanda Capital. Mills told the BBC that his position as a government adviser did not play a role in the decision to contract Ayanda Capital.

The government recalled the masks after The Good Law Project, a nonprofit legal-rights organization, launched a legal challenge over the government's PPE contracts. The group published the government's decision on its website Thursday.

The masks "will not be used in the NHS" because "there was concern as to whether the[y] ... provided an adequate fixing," the UK government said, according to the project.

The masks alone are worth between £156 million and £177 million ($205 million and $233 million), the legal-rights group estimated.

In legal filing made public by the project on Thursday, lawyers for Ayanda Capital said that "the FFP2 masks supplied by our client met contractual requirements."

Ayanda Capital also supplied the NHS with 150 million Type IIR masks, but these have not been recalled.

The Department of Health and Social Care told Business Insider it was unable to comment due to ongoing legal proceedings.

However, a UK government spokesperson told the BBC: "There is a robust process in place to ensure orders are of high quality and meet strict safety standards, with the necessary due diligence undertaken on all government contracts."

In a statement published by the BBC, Ayanda Capital said: "The masks supplied went through a rigorous technical assurance programme and meet all the requirements of the technical specifications which were made available online through the government's portal."

"There are provisions in our contract for product to be rejected if it did not meet the required specification as per the contract. These provisions have not been activated."