In May, this programme revealed that 200 million items of personal protective equipment (PPE) in the UK stockpile had expired by the time Covid-19 was declared a pandemic.
The government and Public Health England insisted at the time that all the expired PPE had been tested and was safe to use.
But tonight we can reveal that safety concerns have been raised over 85 million expired surgical masks and respirators that were distributed to hospitals, care homes and GPs from the stockpile.
Millions have now been withdrawn from use.
Our Health and Social Care Editor Victoria Macdonald has the story.