Fifty million face masks bought by the government in April will not be used in the NHS because of safety concerns.
The government says the masks, which use ear-loop fastenings rather than head loops, may not fit tightly enough.
They were bought for healthcare workers from supplier Ayanda Capital as part of a £252m contract.
Ayanda says the masks met the specifications the government had set out. The government says its safety standards process is “robust”.
It has emerged that the person who originally approached the government about the deal was a government trade adviser who also advises the board of Ayanda.